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I 


SCIENCE 


SHOKT  CHAPTEES. 


BY 

W.  MATTIEU  WILLIAMS,  F.R.A.S.,  F.C.S. 


AUTHOR  OP 


Tfie  Fuel  of  the  Sun,"  "  TJirougJi  Norway  with  a  Knapsack,' 
"A  Simple  Treatise  on  Heat,"  etc. 


YORK: 

JOHN  B.   ALDEN,   PUBLISHER. 
1883. 


CO 

PREFACE. 


I  AM:  not  aware  that  this  reprint  of  some  of  my  scattered 
notes  arid  essays  demands  any  apology. 

The  practice  of  making  such  collections  and  selections 
\  by  the  author  himself  has  now  become  very  general,  and  is 
N  much  better  done  thus  than  by  friends  after  his  death. 

Besides  this,  it  supplies  a  growing  want  of  these  busy 
times,  when  so  many  of  us  are  prevented  by  the  struggles 
of  business  from  sitting  down  to  the  consecutive  systematic 
study  of  a  formal  treatise. 

I  have  kept  this  demand  steadily  in  view  throughout,  by 
selecting  subjects  which  are  likely  to  be  interesting  to  all 
readers  who  are  sufficiently  intelligent  to  prefer  sober  fact 
to  sensational  fiction,  but  who,  at  the  same  time,  do  not 
profess  to  be  scientific  specialists. 

In  the  writing  of  these  papers  my  highest  literary  am- 
f*  bition  has  always  been  to  combine  clearness  and  simplicity 
with  some  attempt  at  philosophy. 

W.  M.  W. 
WILLESDEN,  September,  1882. 


< 


'r(J 


CONTENTS. 


PAGE 

Tbe  Fuel  of  the  Sun 7 

Dr.  Siemens'  Theory  of  the  Sun 38 

Another  World  Down  Here. 41 

The  Origin  of  Lunar  Volcanoes 50 

Note  on  the  Direct  Effect  of  Sun-Spots  on  Terrestrial  Climates. .     56 
The  Philosophy  of  the  Radiometer  and  its  Cosmical  Revelations.     59 

On  the  Social  Benefits  of  Paraffin 65 

The  Solidity  of  the  Earth 72 

A  Contribution  to  the  History  of  Electric  Lighting 75 

The  Formation  of  Coal 88 

The  Solar  Eclipse  of  1871 93 

Meteoric  Astronomy : 104 

The  "  Great  Ice  Age"  and  the  Origin  of  the  "  Till " 112 

The  Barometer  and  the  Weather 140 

Tiie  Chemistry  of  Bog  Reclamatipn .*. 159 

Aerial  Exploration  of  the  Arctic  Regions 170 

The  Limits  of  our  Coal  Supply 189 

"  The  Englishman's  Fireside" 213 

"  Baily's  Beads" 221 

The  Coloring  of  Green  Tea 223 

"Iron  Filings"  in  Tea 227 

Concert-Room  Acoustics 231 

Science  and  Spiritualism 237 

Mathematical  Fictions 251 

World-Smashing 257 


6  CONTENTS. 

PAGE 

The  Dying  Trees  in  Kensington  Gardens. 261 

The  Oleaginous  Products  of  Thames  Mud:  Where  they  Come 

from  and  Where  they  Go 266 

Luminous  Paint 269 

The  Origin  and  Probable  Duration  of  Petroleum 273 

The  Origin  of  Soap 281 

Oiling  the  Waves '. 285 

On  the  so-called  "Crater  Necks"  and  "Volcanic  Bombs"  of 

Ireland 290 

Travertine - 296 

The  Action  of  Frost  in  Water-Pipes  and  on  Building  Materials.  300 

The  Corrosion  of  Building  Stones 308 

Fire-Clay  and  Anthracite 312 

Count  Rumford's  Cooking-Stoves 320 

The  "  Consumption  of  Smoke" 327 

The  Air  of  Stove-Heated  Rooms 332 

Ventilation  by  Open  Fireplaces 337 

Domestic  Ventilation 341 

Home  Gardens  for  Smoky  Towns 351 

Solids,  Liquids,  and  Gases „ 367 

Murchison  and  Babbage 386 

Atmosphere  versus  Ether 389 

A  Neglected  Disinfectant 393 

Another  Disinfectant 393 

Ensilage  394 

The  Fracture  of  Comets 396 

The  Origin  of  Comets 398 


SCIENCE  IN  SHORT  CHAPTERS. 


THE  FUEL  OF  THE  SUN. 

I  OFFER  the  following  sketch  of  the  main  argument  which 
is  worked  out  more  fully  in  the  essay  I  published  in  Janu- 
ary, 1870,  under  the  above  title,  hoping  that,  many  who 
hesitate  to  plunge  into  a  presumptuous  speculative  work 
of  more  than  20(>  octavo  pages  may  read  this  article,  and 
reflect  upon  the  subject. 

The  book  has  been  handled  in  a  most  courteous  and 
indulgent  spirit  by  all  the  reviewers  who  have  noticed  it, 
but  none  have  ventured  to  grapple  with  the  argument  it 
contains,  although  every  possible  opportunity  and  provoca- 
tion for  doing  so  is  designedly  afforded.  It  all  rests  upon 
the  question  which  is  discussed  in  the  first  three  chapters, 
viz.,  whether  the  atmosphere  which  surrounds  our  caith  is 
limited  or  unlimited  in  extent?  If  my  reasoning  upon  this 
fundamental  question  is  refuted,  all  that  follows  necessarily 
falls  to  theground.  If  I  am  right,  all  our  standard  treatises 
on  pneumatics  and  meteorology,  which  repeat  the  arguments 
contained  in  Dr.  Wollaston's  celebrated  paper,  must  be  re- 
modeled. At  the  outset,  I  reprint  that  paper,  and  point 
out  a  very  curious  and  monstrous  fallacy  which,  for  half  a 
century,  remained  undetected,  and  had  been  continually 
repeated. 

As  the  main  point  of  issue  between  myself  and  Dr.  Wol- 
laston  is  merely  a  question  of  very  simple  arithmetic  and 

fometry,  nothing  can  be  easier  than  to  set  me  right  if 
am  wrong:  and,  as  the  philosophical  consequences  de- 
pending upon  this  issue  are  of  vast  and  fundamental  import- 
ance, the  question  cannot  be  ignored  by  those  who  stand 
before  the  world  as  scientific  authorities,  without  a  practical 


S  SCIENCE  IN  SHORT  CHAPTERS. 

abdication  of  their  philosophical  responsibilities.  Any  man 
who  publishes  an  astronomical  or  meteorological  treatise 
without  discussing  this  question,  which  stands  before  him  at 
the  threshold  of  his  subject,  is  unfit  for  the  task  he  has 
undertaken,  and  unworthy  of  public  confidence.  This  may 
appear  a  strong  conclusion  just  now,  but  a  few  years  will  be 
sufficient  to  graft  it  firmly  into  the  growth  of  scientific 
public  opinion.* 

"  The  Fuel  of  the  Sun"  is  simply  an  attempt  to  trace 
some  of  the  consequences  which  must  of  necessity  result 
from  the  existence  of  an  universal  atmosphere,  and  it  differs 
from  other  attempts  to  explain  the  great  solar  mystery,  by 
making  no  demands  whatever  upon  the  imagination,  in- 
renting  nothing, — no  outside  meteors,  no  new  forces  or 
materials.  It  supposes  nothing  whatever  to  exist  but  the 
known  facts  of  the  laboratory— the  familiar  materials  of 
the  earth  and  its  atmosphere.  It  is  shown  that  these  mate- 
rials and  the  forces  residing  within  them  must  of  necessity 
produce  a  sun,  and  manifest  eternally  all  the  observed  solar 
phenomena,  provided  only  they  are  aggregated  in  the  quan- 
tities which  our  own  central  luminary  presents,  and  are 
surrounded  by  attendant  planets,  suoh  as  his.  Nothing  is 
assumed  or  taken  for  granted  beyond  the  simple  funda- 
mental hypothesis  that  the  laws  of  nature  are  uniform 
throughout  the  universe.  The  argument  thus  conducted 
leads  us  step  by  step  to  a  natural  and  connected  explanation 
of  the  following  important  phenomena: — 

1.  The  sources  of  solar  and  stellar  heat  and  light. 

2.  The  means  by  which  the  present  amount  of  solar  heat 
and  light  must  be  maintained  so  long  as  the  solar  system 
continues  in  existence. 

3.  The  origin  of  the  general  and  particular  phenomena 
of  the  sun-spots. 

*  Up  to  the  present  date  (1882)  nobody,  as  far  as  I  know,  has 
questioned  my  figures  or  defended  those  of  Wollaston.  Sir  William 
Grove  has  written  to  me,  pointing  out  his  own  anticipations  of  my 
conclusions  respecting  the  universality  of  atmospheric  matter.  Sir 
Charles  Lyell,  before  his  death,  expressed  very  strong  approval  of  my 
conclusions,  and  many  other  men  of  scientific  eminence  have  done 
the  same.  To  expect  any  immediate,  unreserved  adoption  of  such 
bold  speculations  would  be  unreasonable. 


THE   FUEL   OF  THE  SUN.  9 

4.  The  cause  of  the  varying  splendor  of  the  photosphere, 
including  such  details  as  the  "  faculae,"  "  mottling,"  "  gran- 
ulations," etc.,  etc. 

5.  The  forces  which  upheave  the  solar  prominences. 

6.  The  origin  of  the  corona  and  zodiacal  light. 

7.  The  origin  of  the  meteorites  and  the  asteroids. 

8.  The  meteorological  phenomena  of  the  planets. 

9.  The  origin  of  the  rings  of  Saturn. 

10.  The  origin  of  the  special  structure  of  the  nebulae. 

11.  The  source  of  terrestrial  magnetism,  and  its  connec- 
tion with  solar  activity. 

The  first  and  second  chapters  are  devoted  to  an  examina- 
tion of  the  limits  of  atmospheric  expansibility.  The  ex- 
perimental investigations  of  Dr.  Andrews,  Mr.  Grove,  Mr. 
Gassiot,  and  M.  Geissler  are  cited  to  prove  that  the  expansi- 
bility of  the  atmosphere  is  unlimited,  and  other  cosmical 
evidence  is  adduced  in  support  of  this  conclusion. 

As  this,  which  is  really  the  foundation  of  the  whole  argu- 
ment, is  directly  opposed  to  the  views  expressed  by  Dr. 
Wollaston,  in  his  celebrated  paper  on  "  The  Finite  Extent 
of  the  Atmosphere,"  published  in  1822,  and  generally  ac- 
cepted as  established  science,  this  paper  is  reprinted  in  the 
second  chapter,  and  carefully  examined. 

Dr.  Wollaston  says  "that  air  has  been  rarefied  so  as  to 
sustain  l-100th  of  an  inch  of  barometrical  pressure,"  and 
further,  that  "  beyond  this  limit  we  are  left  to  conjectures 
founded  on  the  supposed  divisibility  of  matter;  if  this  be 
infinite,  so  also  must  be  the  extent  of  our  atmosphere." 

I  contend  that  our  knowledge  of  the  whole  subject  is 
fundamentally  altered  since  these  words  were  written.  We 
are  no  longer  ''left  to  conjectures  founded  on  the  supposed 
divisibility  of  matter"  to  determine  the  possibility  of  further 
expansibility  than  that  indicated  by  l-100th  of  an  inch  of 
barometrical  pressure,  as  we  now  have  means  of  obtaining 
ten  times,  a  hundred  times,  a  thousand  times,  or  even  an 
infinitely  greater  rarefaction  than  Wollaston's  supposed 
limit,  an  apparently  absolute  vacuum  being  now  obtainable: 
and  although  the  transmission  of  electricity  affords  a  means 
of  testing  the  existence  of  atmospheric  matter  with  a  degree 
of  delicacy  of  which  Wollaston  had  no  conception,  we  are 


10  SCIENCE  IN  SHORT  CHAPTERS. 

still  unable  to  detect  any  indication  of  any  limit  to  its  ex- 
pansibility. 

The  most  remarkable  part  of  Dr.  Wollaston's  paper  is 
the  reductio  ad  absurdum  by  which  he  seeks  to  finally  demon- 
strate the  finite  extent_of  our  atmosphere.  He  maintains, 
as  I  do,  tluit  if  the  elasticity  of  our  atmosphere  is  unlimited, 
its  extension  must  be  commensurate  with  the  universe,  that 
every  orb  in  space  will,  by  gravitation,  gather  around  itself 
an  atmosphere  proportionate  to  its  gravitating  power,  and 
that,  by  taking  the  known  quantity  of  the  earth's  atmos- 
phere as  our  unit,  we  may  calculate  the  amount  of  atmos- 
phere possessed  by  any  heavenly  body  of  which  the  mass  is 
known.  On  this  basis  Dr.  Wollaston  calculates  the  atmos- 
phere of  the  sun,  and  concludes  that  its  extent  will  be  so 
great  as  to  visibly  affect  the  apparent  motions  of  Mercury 
and  Venus,  when  their  declination  makes  its  nearest  ap- 
proach to  that  of  the  sun.  No  such  disturbance  being 
actually  observable,  he  concludes  that  such  an  atmosphere 
as  he  has  calculated  cannot  exist.  In  like  manner  he  cal- 
culates the  atmosphere  of  Jupiter,  and  finds  it  to  be  so 
great,  that  its  refraction  would  be  sufficient  "  to  render  the 
fourth  satellite  visible  to  us  when  behind  the  centre  of  the 
planet,  and  consequently  to  make  it  appear  on  both  (or  all) 
sides  at  the  same  time." 

On  examining  these  calculations,  I  have  discovered  the 
very  curious  error  above  referred  to.  As  this  is  a  matter 
of  figures  that  cannot  be  abridged,  I  must  refer  the  reader 
to  the  original  calculations.  I  will  here  merely  state  that 
Wollaston's  method  of  calculating  the  solar  gravitation  at- 
mosphere and  that  of  Jupiter  and  the  moon  leads  to  the 
monstrous  conclusion  that,  in  ascending  from  the  surface 
of  the  given  orb,  we  always  have  the  same  limited  amount 
of  atmospheric  matter  above  as  that  with  which  we  start- 
ed, although  we  are  continually  leaving  a  portion  of  it 
below. 

Wollaston's  mistake  is  based  on  the  assumption  that, 
under  the  circumstances  supposed,  the  atmospheric  pres- 
sure and  density,  at  any  given  distance  from  the  centre  of 
the  given  orb,  will  vary  inversely  with  the  square  of  that 
distance.  As  the  area  of  the  base  upon  which  such  pressure 


THE  FUEL   OF  THE  SUN.  11 

is  exerted  varies  directly  with  the  square  of  the  distance, 
the  total  atmosphere  above  every  imaginable  starting-dis- 
tance would  thus  be  ever  the  same.  That  this  assumption, 
so  utterly  at  variance  with  the  known  laws  of  atmos- 
pheric distribution,  should  have  remained  unchallenged  for 
half  a  century,  and  that  the  conclusions  based  upon  it 
should  be  accepted  by  the  whole  scientific  world,  and  re- 
peated in  standard  treatises,  such  as  those  of  the  "  Encyclo- 
pedia Britannica,"  etc.,  etc.,  is,  I  think,  one  of  the  most 
remarkable  curiosities  presented  by  the  history  of  science. 
If  it  were  merely  a  little  cobweb  in  some  obscure  corner  of 
philosophy,  there  would  be  nothing  surprising  in  its  escape 
from  the  besom  of  scientific  criticism;  but  this  is  so  far 
from  being  the  case,  that  it  has  hung,  since  1822,  like  a 
dark  veil  obscuring  another,  a  wider,  and  more  interesting 
view  of  the  universe  which  the  idea  of  an  universal  atmos- 
phere opens  out.  But  I  must  now  proceed  to  the  next 
stage  of  the  argument. 

Starting  from  the  conclusion  reached  in  the  previous 
chapters,  that  the  atmosphere  of  our  earth  is  but  a  portion 
of  an  universal  elastic  medium  which  it>  has  attached  to 
itself  by  its  gravitation,  and  that  all  the  other  orbs  of  space 
must,  in  like  manner,  have  obtained  their  proportion,  I 
take  the  earth's  mass,  and  its  known  quantity  of  atmos- 
pheric envelope  as  units,  and  calculating  by  the  simple 
rule  I  have  laid  down  in  opposition  to  Wollaston's,  I  find 
that  the  total  weight  of  the  sun's  atmosphere  should  be  at 
least  117,681,623  times  that  of  the  earth's,  and  the  pres- 
sure at  its  base  equal,  at  least,  to  15,233  atmospheres. 
What  must  be  the  results  of  such  an  atmospheric  accumu- 
lation? 

The  experiment  of  compressing  air  in  the  condensing 
syringe,  and  thereby  lighting  a  piece  of  German  tinder,  is 
familiar  to  all  who  have  studied  even  the  rudiments  of  phys- 
ical science.  Taking  the  formulae  of  Leslie  and  Dalton, 
and  applying  them  to  the  solar  pressure  of  15,233  ;itmos- 
phercs,  we  arrive  according  to  Leslie,  at  the  inconceivable 
temperature  of  380,832°  C.,  or  685,529°  F.,  as  that  due  to 
this  amount  of  compression,  or,  according  to  Dalton,  at 
761,665°  F.  What  will  be  the  effects  of  such  a  degree  of 


12  SCIENCE  IN  SHOUT  CHAPTERS. 

heat  upon  materials  similar  to  those  of  which  our  earth  is 
composed? 

Let  us  first  take  the  case  of  water,  which,  for  reasons  I 
have  stated,  should  be  regarded  as  atmospheric,  or  univer- 
sally diffused  matter. 

This  brings  us  to  a  subject  of  the  highest  and  widest 
philosophical  and  practical  importance.  I  refer  to  the  an- 
tagonism between  the  force  of  heat  and  that  of  chemical 
combination,  to  which  the  French  chemists  have  given 
the  name  "dissociation."  Having  myself  been  unable  to 
find  any  satisfactory  English  account  of  this  subject  at  a 
time  when  it  had  already  been  well  treated  by  French  and 
German  authors,  in  the  form  of  published  lectures  and 
cyclopasdia  articles,  I  assume  that  others  may  have  en- 
countered a  similar  difficulty,  and  therefore  dwell  rather 
more  fully  upon  this  part  of  my  present  summary. 

It  appears  that  all  chemical  compounds  may  be  decom- 
posed by  heat,  and  that,  at  a  given  pressure,  there  is  a  def- 
inite and  special  temperature  at  which  the  decomposition 
of  each  compound  is  effected.  For  the  absolute  and  final 
establishment  of  the  universality  of  this  law  further  investi- 
gations are  necessary,  actual  investigations  having  estab- 
lished it  as  far  as  they  have  gone,  but  these  have  not  been 
exhaustive. 

There  appears  to  be  a  remarkable  analogy  between  dis- 
sociation and  evaporation.  When  a  liquid  is  vaporized,  a 
certain  amount  of  heat  is  "rendered  latent/'  and  this  quan- 
tity varies  with  the  liquid  and  with  the  pressure,  but  is 
definite  and  invariable  for  each  liquid  at  a  given  pressure. 
In  like  manner,  when  a  compound  is  dissociated,  a  certain 
amount  of  heat  is  "  rendered  latent,"  or  converted  into  dis- 
sociating force,  and  this  varies  with  each  compound  and 
with  the  pressure,  but  is  definite  and  invariable  for  each 
compound  at  a  given  pressure.  Further,  when  condensa- 
tion occurs,  an  amount  of  heat  is  evolved,  as  temperature, 
exactly  equal  to  that  which  was  rendered  latent  in  the  evap- 
oration of  the  same  substance  under  the  same  pressure;  and, 
in  like  manner,  when  chemical  re-combination  of  dissociated 
elements  occurs,  an  amount  of  heat  is  evolved,  as  tempera- 
ture, exactly  equal  to  that  which  disappeared  when  the 


THE  FUEL   OF  TEE  SUN.  13 

compound  was  dissociated  by  heat  alone  under  the  same 
pressure. 

According  to  the  recently  adopted  figures  of  M.  Deville, 
the  temperature  at  which  the  vapor  of  water  becomes  dis- 
sociated under  ordinary  atmospheric  pressure  is  2800°  C., 
and  the.  quantity  of  heat  which  disappears,  as  temperature, 
in  the  course  of  dissociation  is  2153  calorics,  i.e.,  sufficient 
to  raise  2153  times  its  own  weight  of  liquid  water  1°  C.; 
but,  as  the  specific  heat  of  aqueous  vapor  is  to  that  of  liquid 
water  as  0'47o  to  1,  that  latent  heat  expressed  in  the  tem- 
perature it  would  have  given  to  aqueous  vapor  is  =  4532° 
C.,  or  8158°  F. 

In  order  to  render  the  analogy  between  the  ebullition  and 
dissociation  of  water  more  evident  and  intelligible,  I  will 
state  it  as  follows: — 

To  commence  the  ebullition  of      T°  commence  the  dissociation  of 

water  under  ordinary  pressure,          aqueous  vapor  under  ordinary 

a  temperature  of  100°  C.,  or          pressures,    a    temperature    of 

212°  F    must  be  attained  2800°  c->  or  5072°  F.,  must  be 

attained. 

To  complete  the  ebullition  of  a  To  complete  the  dissociation  of 

given   quantity  of  water,    an  a  given  quantity  of  aqueous 

amount  of  heat  must  be  ap-  vapor,  an  amount  of  heat  must 

plied,  sufficient  to  have  raised  be  applied   sufficient  to  have 

the  water  537°  C.,  or  968°  F.,  raised  the  vapor  4532°  C.,  or 

above  its  boiling-point,  had  it  8158°  F.,  above  its  dissociation- 

not  evaporated.  point  had  it  not  decomposed. 

In  order  that  a  given  quantity  of  In  order  that  a  given  quantity  of 
vapor  of  water  shall  condense,  the  elements  of  water  may  corn- 
it  must  give  off  sufficient  heat  bine,  they  must  give  off  suffi- 
to  raise  'its  own  weight  of  wa-  dent  heat  to  raise  their  own 
ter  537°  C.,  or  968°  F.  weight  of  aqueous  vapor  4532° 

C.,  or  8158°  F. 

I  have  expressed  these  generalizations  and  analogies  rather 
more  definitely  than  they  have  been  hitherto  stated,  but 
those  who  are  acquainted  with  the  researches  of  Deville, 
Cailletet,  Bunsen,  etc.,  will  perceive  that  I  am  justified  in 
doing  so.* 

*  Since  the  above  was  written  these  analogies  have  been  generally 
accepted. 


14  SCIENCE  IN  SHORT  CHAPTERS. 

With  the  general  laws  of  the  dissociation  of  water  thus 
before  us,*  we  may  follow  out  the  necessary  action  of  the 
above-stated  pressure  and  consequent  evolution  of  heat  in 
the  lower  regions  of  the  solar  atmosphere  upon  the  large 
proportion  of  aqueous  vapor  which  I  have  shown  that  it 
should  contain. 

It  is  evident  that  the  first  result  will  be  separation  of 
this  water  into  its  elements,  accompanied  with  a  loss  of 
temperature  corresponding  to  the  latent  heat  of  dissocia- 
tion. We  may  assume  that  in  the  lower  regions  of  the  solar 
atmosphere  the  free  heat  evolved  by  mechanical  compression 
will  be  more  than  sufficient  to  dissociate  the  whole  of  the 
aqueous  vapor,  and  thus  the  dissociated  gases  will  be  left 
at  a  higher  temperature  than  was  necessary  to  effect  their 
dissociation.  Their  condition  will  thus  be  analogous  to  that 
of  superheated  steam:  they  will  have  to  give  off  some  heat 
before  they  can  begin  to  combine.* 

There  will,  however,  be  somewhere  an  elevation  at  which 
the  heat  evolved  by  the  joint  compression  of  the  elementary 
and  combined  gases  will  be  just  sufficient  to  dissociate  the 
latter,  and  here  will  be  the  meeting  surface  of  the  combined 
and  the  uncombined  constituents  of  water.  There  will  be 
a  sphere  containing  combined  oxygen  and  hydrogen  sur- 
rounded by  an  atmospheric  envelope  containing  large  quan- 
tities of  aqueous  vapor,  and  the  temperature  at  this  limiting 
surface  will  be  equal  to  that  of  the  oxyhydrogen  flame 
under  a  corresponding  pressure. 

What  will  occur  under  these  conditions?     Will  the  "  de- 


*  Since  the  publication  of  "The  Fuel  of  the  Sun,"  Mr.  Norman 
Lockyer  has  adopted  this  view  of  solar  dissociation,  and  has  gone  so 
far  ns*  to  suppose  that  it  splits  metals  and  other  substances  regarded  by 
modern  chemists  as  simple  elements  into  more  elementary  and  simple 
constituents.  He  assumes  that  the  temperature  of  the  solar  atmos- 
phere, growing  higher  at  increasing  depths,  becomes  somewhere  cap- 
able of  "doing  far  greater  dissociation  work  than  that  which  separates 
the  hydrogen  of  the  prominences  revealed  by  the  spectroscope.  In 
putting  forth  this  "working  hypothesis"  he  seems  to  have  lost  sight 
of  the  fact  clearly  proved  by  Deville's  experiments,  that  the  tempera- 
ture of  dissociation  rises  with  the  pressure  to  which  the  compound  is 
subjected,  and  thus  that  within  the  bowels  of  the  sun  the  metals  will 
be  far  less  dissociable  than  they  art  on  the  surface  of  our  earth. 


THE  FUEL  OF  THE  SUN.  15 

tonating  gases  "  behave  as  in  the  laboratory?  Obviously  not, 
as  a  glance  at  the  third  of  the  above  parallel  propositions 
will  show.  The  dissociated  gases  cannot  combine  without 
giving  off  their  4532°  of  latent  heat  as  actual  temperature. 
This  can  only  be  effected  by  communication  with  matter 
which  is  cooler  than  itself. 

If  a  bubble  of  steam  is  surrounded  by  water  maintained 
at  the  boiliug  temperature,  it  will  not  condense  at  all,  be- 
cause any  effort  of  condensation  would  be  accompanied 
with  an  evolution  of  heat  exactly  sufficient  to  evaporate  its 
own  result.  If,  however,  the  surrounding  water  is  slowly 
radiating,  or  otherwise  losing  its  heat,  the  enclosed  bubble 
of  steam  will  condense  proportionately,  by  giving  off  to  its 
envelope  an  amount  of  its  latent  heat  just  sufficient  to  main- 
tain the  water  at  the  boiling-point. 

For  further  illustration,  let  us  conceive  the  case  of  a  cer- 
tain quantity  of  the  elements  of  water  heated  exactly  to  the 
temperature*  of  dissociation,  and  confined  in  a  vessel  the 
sides  of  which  are  maintained  externally  at  precisely  the 
same  temperature  as  the  gases  within,  so  that  no  heat  can 
be  added  or  taken  away  from  them.  No  sensible  amount 
of  combination  can  take  place,  as  the  first  infinitesimal 
effort  of  combustion,  or  combination,  would  set  free  just  the 
amount  of  heat  required  to  decompose  its  own  result.  Let 
us  now  suppose  a  modification  of  these  conditions,  viz., 
that  the  vessel  containing  the  dissociated  gases,  at  the  tem- 
perature of  dissociation,  shall  be  surrounded  with  bodies 
cooler  than  itself,  i.e.,  capable  of  receiving  more  heat  from 
it  than  they  radiate  towards  it ;  there  would  then  take 
place  just  so  much  combustion  as  would  set  free  the  amount 
of  heat  required  to  maintain  the  temperature  of  the  vessel 
at  the  dissociation-point ;  or,  in  other  words,  combustion 
would  go  on  to  the  extent  of  setting  free  just  so  much  heat 
as  the  gaseous  mass  was  capable  of  radiating,  or  otherwise 
transmitting  to  surrounding  bodies ;  and  this  amount  of 
combustion  would  continue  till  all  the  gases  had  combined. 

We  have  only  to  give  this  hypothetical  vessel  a  spherical 
form  and  an  internal  diameter  of  853,380  miles — to  con- 
struct its  enveloping  sides  of  a  thick  shell  of  aqueous  vapor, 
etc.,  and  then,  by  placing  in  the  midst  of  the  contained  dis- 


16  SCIENCE  IN  SHORT  CHAPTERS. 

sociated  gases  a  nucleus  of  some  kind,  we  are  hypothetic- 
ally  supplied  with  the  main  conditions  which  I  suppose  to 
exist  in  the  sun. 

A  little  reflection  upon  the  application  of  the  above- 
stated  laws  to  these  conditions  will  show  that  the  stupen- 
dous ocean  of  explosive  gases  would  constitute  an  enormous 
stock  of  fuel  capable,  by  its  combustion,  of  setting  free  ex- 
actly the  same  quantity  of  heat  as  had  previously  been  con- 
verted into  decomposing  or  separating  force ;  the  amount 
of  combustion  would  always  be  limited  by  the  possible 
amount  of  radiation,  and  the  radiation  would  again  be  lim- 
ited by  the  resisting  envelope  of  aqueous  vapor  produced  by 
this  combustion. 

If  these  conditions  existed  in  a  perfectly  calm  and  undis- 
turbed solar  atmosphere,  there  would  be  a  continally  in- 
creasing external  envelope  of  aqueous  vapor,  and  a  contin- 
ually diminishing  inner  atmosphere  of  combustible  gases  ; 
there  would  be  a  gradual  diminution  of  the  amount  of  solar 
radiation,  and  a  slow  and  perpetually  retarding  progress 
towards  solar  extincton. 

It  should  be  noted  that,  according  to  this  explanation, 
the  supply  of  heat  is  originally  derived  from  atmospheric 
condensation  due  to  gravitation,  that  the  storage  of  surplus 
heat  is  effected  by  dissociation,  and  its  evolution  mainly  by 
recombination  or  combustion. 

The  great  difficulty,  that  of  the  perpetual  renewal  of  the 
solar  fuel,  still  remains  unsolved  ;  the  fact  that  during  the 
millions  of  years  of  geological  history  we  find  no  indications 
of  any  declining  average  of  solar  energy  is  so  far  still  unex- 
plained by  this,  as  by  every  other,  attempt  to  account  for 
the  origin  of  solar  and  stellar  light  and  heat. 

In  his  inaugural  address  to  the  British  Association  Meet- 
ing of  1 866,  Mr.  Grove  put  the  following  very  suggestive 
question: —  "  Our  sun,  our  earth,  and  planets  are  constantly 
radiating  heat  into  space  ;  so,  in  all  probability,  are  the 
other  suns,  the  stars,  and  their  attendant  planets.  What 
becomes  of  the  heat  thus  radiated  into  space  ?  If  the  uni- 
verse has  no  limit — and  it  is  difficult  to  conceive  one — there 
is  a  constant  evolution  of  heat  and  light ;  and  yet  more  is 
given  off  than  is  received  by  each  cosmical  body,  for  other- 


THE  FUEL  OF  THE  SUN.  17 

wise  night  would  be  as  light  and  as  warm  as  day.  What 
becomes  of  the  enormous  force  thus  apparently  non-recur- 
rent in  the  same  form? 

This  is  a  grand  question,  a  philosophical  thought  worthy 
of  the  author  of  ' '  The  Correlation  of  Physical  Forces." 
Most  philosophical  thinkers  will,  I  believe,  agree  with  me  in 
concluding  that  a  sound  reply  to  it  will  solve  the  great  mys- 
tery of  the  everlasting  radiations  of  our  sun  and  all  the  other 
suns  of  the  universe.  So  long  as  we  regard  these  suns  as 
the  sources  of  continually  expended  forces  of  light  and  heat, 
their  everlasting  and  unabated  renewal  becomes  a  mystery 
utterly  inscrutable  to  the  human  intellect,  since  the  creation 
of  new  force,  or  any  addition  to  the  total  forces  of  the 
universe,  is  as  inconceivable  to  us  as  any  addition  to  the 
total  matter  of  the  universe.  The  great  solar  question  as- 
sumes a  far  more  hopeful  shape  when  we  admit  that  all  the 
forces  of  past  radiations  are  somewhere  diffused  in  space, 
and  we  ask  whether  a  sun  contains  any  mechanism  by 
which  it  may  collect  and  concentrate  this  diffused  force,  and 
thus  perpetually  gather  from  surrounding  suns  as  much  as 
it  radiates  towards  them. 

The  next  part  of  my  work  is  an  attempt  to  show  that  such 
a  mechanism  does  exist  in  our  solar  system,  and  to  explain 
its  action. 

Ws  know  that  if  atmospheric  air  is  compressed  it  becomes 
heated,  that  if  this  heat  is  allowed  to  radiate  and  the  air  is 
again  expanded  to  its  original  dimensions,  it  will  be  cooled 
below  its  original  temperature  to  an  extent  precisely  equal 
to  the  heat  which  it  gave  out  when  compressed.  On  this 
principle  I  endeavor  to  explain  the  everlasting  maintenance 
of  the  solar  and  stellar  radiations. 

The  sun  is  attended  by  his  train  of  planets  whose  orbital 
motion  he  controls,  but  they  in  return  react  upon  him  as 
the  moon  does  upon  the  earth.  If  this  reaction  were  reg- 
ular, like  that  of  the  moon  upon  the  earth,  a  regular  at- 
mospheric tide  would  result ;  but  the  great  irregularity  of 
the  dimensions,  distances,  and  velocities  of  the  planets  pro- 
duces a  result  equivalent  to  a  number  of  clashing  irregular 
tides  in  the  solar  atmosphere ;  or,  otherwise  stated,  the 
centre  of  motion  and  centre  of  gravity  of  the  whole  system 


18  SCIENCE  IN  SHORT  CHAPTERS. 

will  be  perpetually  varying  with  the  varying  relative  posi- 
tions of  the  planets,  and  thus  the  solar  nucleus  and  solar 
atmosphere  will  be  subject  to  irregularities  of  motion,  which, 
though  very  small  relatively  to  the  enormous  magnitude  of 
the  sun,  must  be  sufficient  to  produce  mighty  vortices,  and 
thus  effect  a  continual  commingling  between  the  outer  and 
inner  atmospheric  strata. 

It  must  be  remembered  that,  according  to  the  preceding, 
the  inner  or  lower  strata  of  the  solar  atmosphere  should 
consist  of  our  ordinary  atmospheric  mixture  of  oxygen  and 
nitrogen,  and  the  dissociated  elements  of  water  and  carbonic 
acid,  besides  some  of  the  more  volatile  elements  of  the  solar 
nucleus.  Outside  of  this  there  should  be  a  boundary  limit 
where  the  dissociated  gases  are  combining  as  rapidly  as 
their  latent  heat  can  be  evolved  by  radiation;  this  will 
form  a  shell  or  sphere  of  flame,— the  photosphere, — and 
above  or  beyond  this  will  be  the  sphere  of  vapors  resulting 
from  this  combustion,  which,  by  their  resistance  to  radia- 
tion, will  limit  the  evolution  of  heat  and  consequent  com- 
bustion. 

Now  the  vortices  above  referred  to  will  break  through  the 
shell  of  combustion,  and  drag  down  more  or  less  of  the 
outer  vapor  into  the  lower  and  hotter  regions  of  dissocia- 
ted gases. 

As  there  can  be  no  action  without  equal  and  contrary 
reaction,  there  can  be  no  vortices,  either  in  the  solar  atmos- 

Ehere  or  a  terrestrial  stream,  without  corresponding  up- 
eavals.  These  upheavals  will  eject  the  lower  dissociated 
gases  more  or  less  completely  through  the  vaporous  jacket 
which  restrains  their  normal  radiations,  and,  thus  liberated, 
they  will  rush  into  combination  with  an  explosive  energy 
comparable  to  that  which  they  display  in  our  laboratories; 
not,  however,  with  an  instantaneous  flash,  but  with  a  con- 
tinuous rocket-like  combustion,  the  rapidity  of  which  will  be 
determined  by  the  possibility  of  radiation.  The  heat 
evolved  by  this  combustion,  acting  simultaneously  with  the 
diminution  of  pressure,  will  effect  a  continually  augment- 
ing expansion  of  these  upheaved  gases,  and  as  the  rapidity 
of  combustion  will  be  accelerated  in  proportion  to  elevation 
above  the  restraining  vapors,  an  outspreading  far  in  excess 


THE  FUEL   OF  THE  SUN.  19 

of  that  which  would  be  due  to  the  original  upheaving  force, 
is  to  be  expected. 

The  reader  who  is  acquainted  with  the  phenomena  of  the 
solar  prominences  will  at  once  perceive  how  all  these  expec- 
tations are  fulfilled  by  actual  observations,  especially  by  the 
more  recent  observations  of  Zollner,  Secchi,  etc.,  which 
exhibit  the  typical  solar  prominence  as  a  stem  or  jet  rush- 
ing upwards  through  some  restraining  medium,  and  then 
expanding  intoa  cloud-like  or  palm-tree  form  after  escaping 
from  this  restraint.  I  need  scarcely  add  that  the  clashing 
tide  waves  are  the  faculce,  and  the  vortices  the  sun-spots. 

My  present  business,  however,  is  to  show  how  these  vor- 
tices and  eruptions — this  down-rush  in  one  part  of  the 
solar  atmosphere  and-  up- rush  in  another — contribute  to 
the  permanent  maintenance  of  the  solar  light  and  heat.  It 
must  be  understood  that  these  outbursts  are  only  visible  to 
us  as  luminous  prominences  during  the  period  of  their 
explosive  outburst,  and  while  still  subject  to  great  expan- 
sive tension.  Long  after  they  have  ceased  to  be  visible  to 
us  their  expansion  must  continue,  until  they  finally  and 
fully  mingle  with  the  medium  into  which  they  are  flung, 
and  attain  a  corresponding  degree  of  rarefaction.  This 
must  occur  at  tens  and  hundreds  of  thousands  of  miles 
above  the  photosphere,  according  to  the  magnitude  of  the 
ejection.  The  spectroscopic  researches  of  Frankland  and 
Lockyer  having  shown  that  the  atmospheric  pressure  at 
about  the  outer  surface  of  the  photosphere  does  not  far  ex- 
ceed that  of  our  atmosphere,  I  may  safely  regard  all  the 
upper  portion  of  these  solar  ejections-as  "having  left  the 
solar  atmosphere  proper,  and  become  commingled  with  the 
general  interstellar  medium. 

If  the  sun  were  stationary,  or  merely  rotating,  in  the 
midst  of  this  universal  atmosphere,  the  same  material  that 
is  ejected  to-day  would  in  the  course  of  time  return,  and 
be  whirled  into  the  great  sun-spot  eddies;  but  such  is  not 
the  case;  the  sun  is  driving  through  the  ether  with  a  velo- 
city of  about  450,000  miles  per  twenty  four  hours. 

What  must  be  the  consequence  of  this  motion  ?  The  sun 
will  carry  its  own  special  atmospheric  matter  with  it;  but 
it  cannot  thus  carry  the  whole  of  the  interstellar  medium. 


20  SCIENCE  IN  SHORT  CHAPTERS. 

There  must  be  a  limit,  graduated  no  doubt,  but  still  a  prac- 
tical limit,  at  which  its  own  atmosphere  will  leave  behind, 
or  pass  through,  the  general  atmospheric  matter.  There 
must  be  a  heaping  or  condensation  of  this  matter  in  the 
front,  a  rarefaction  or  wake  in  the  rear,  and  a  continuous 
bow  of  newly  encountered  atmosphere  around  the  bounda- 
ries in  the  opposite  direction  to  that  of  the  sun's  motion. 
The  result  of  this  must  be  that  a  great  portion  of  the 
ejected  atmospheric  matter  of  the  prominences  will  be 
swept  permanently  to  the  rear,  and  its  place  supplied  by 
the  material  occupying  the  space  into  which  the  sun  is  ad- 
vancing. We  are  thus  presented  with  a  mighty  machinery 
of  solar  respiration;  some  of  this  newly  arriving  atmos- 
pheric matter  must  be  stirred  into  the  vortices,  its  quantity 
being  exactly  equivalent  to  that  of  the  old  material  expired 
by  the  explosive  eruptions,  and  left  in  the  rear. 

Now,  the  new  atmospheric  matter  which  is  thus  encoun- 
tered and  inspired,  is  the  recipient  of  the  everlasting  radi- 
ations whose  destination  is  the  subject  of  Mr.  Grove's 
inquiry;  and  these,  when  thus  encountered  and  compressed, 
will  of  necessity  evolve  more  or  less  of  the  heat  which, 
through  millions  of  millions  of  centuries  they  have  been 
gradually  absorbing;  while,  on  the  other  hand,  the  expired 
or  ejected  matter  of  the  gaseous  eruptions  will,  like  the 
artificially  compressed  air  above  referred  to,  have  lost  all 
the  heat  which  during  its  solar  existence  it  had  by  compres- 
sion, dissociation,  and  re-combination  contributed  to  the 
solar  radiations.  Therefore,  when  again  fully  expanded,  it 
will  be  cooler  than  the  general  medium  from  which  it  was 
originally  inspired  by  the  advancing  sun. 

The  daily  supply  of  fresh  atmospheric  fuel  will  be  a  cy- 
linder of  ether  of  the  same  diameter  as  the  sun,  and  450,- 
000  miles  in  length!  I  have  calculated  the  weight  of  this 
cylinder  of  ether  on  the  assumption  (which  of  course  is 
purely  arbitrary)  that  the  density  of  the  interstellar  medium 
is  one  ten-thousandth  part  of  that  of  our  atmosphere.  It 
amounts  to  14,313,915,000,000,000,000  tons, affording  a  sup- 
ply of  165  millions  of  millions  of  tons  per  second;  or,  if  we  as- 
sume the  interstellar  medium  to  have  a  density  of  only  one- 
millionth  of  that  of  our  atmosphere,  the  supply  would  be 


THE  FUEL   OF  THE  SUN.  21 

rather  more  than  one  and  a  half  millions  of  millions  of  tons 
per  second.  The  proportion  of  this  which  is  effective  in  the 
manner  above  stated  is  that  which  becomes  stirred  into  the 
lower  regions  of  the  sun  in  exchange  for  the  ejected  matter 
of  the  prominences. 

I  will  not  here  dwell  upon  the  bombardment  hypothesis, 
beyond  observing  that  my  explanation  of  solar  phenomena 
supplies  a  continuous  bombardment  of  the  above-stated 
magnitude  without  adding  anything  to  the  magnitude  of 
the  sun. 

So  far,  then,  I  answer  Mr.  Grove's  question,  by  showing 
that  the  heat  radiated  into  space  by  each  of  the  solid  orbs 
that  people  its  profundities,  is  received  by  the  universal 
atmospheric  medium;  is  gathered  again  by  the  breathing 
of  wandering  suns,  who  inspire  as  they  advance  the  breath 
of  universal  heat  and  light  and  life;  then  by  impact,  com- 
pression, and  radiation,  they  concentrate  and  re-distribute 
its  vitalizing  power;  and  after  its  work  is  done,  expire  it  in 
the  broad  wake  of  their  retreat,  leaving  a  track  of  cool  ex- 
hausted ether — the  ash-pits  of  the  solar  furnaces — to  re- 
absorb  the  general  radiations,  and  thus  maintain  the  eternal 
round  of  life. 

But  ere  this,  a  great  difficulty  has  probably  presented  it- 
self to  the  mind  of  the  reader.  He  will  refer  to  the  calcu- 
lations that  have  been  made  in  order  to  determine  the 
actual  temperature  of  the  solar  surface  and  the  intensity  of 
its  luminosity.  Both  of  these  are  vastly  in  excess  of  those 
obtained  in  our  laboratory  experiments  by  the  combustion 
of  the  elements  of  water.  Even  taking  into  consideration 
the  dissociated  carbonic  acid  whose  elements  should  be 
burning  in  the  photosphere  with  those  of  water,  and  adding 
to  these  the  volatile  metals  of  the  solar  nucleus  whose  dis- 
sociated vapors  must,  under  the  circumstances  stated,  be 
comming  ed  with  those  of  the  solar  atmosphere,  and  there- 
fore con  tribute  to  the  luminosity  by  their  combustion,  still 
by  burning  here  on  the  earth  a  jet  of  such  mixed  gases  and 
vapors  we  should  not  obtain  any  approach  to  either  the  lu- 
minosity or  the  temperature  which  is  usually  attributed  to 
the  sun. 

I  have  made  a  very  few  simple  experiments,  the  results 


22  SCIENCE  IN  SHOUT  CHAPTERS. 

of  which  remove  these  difficulties.  They  were  conducted 
witli  the  assistance  of  Mr.  Jonathan  Wilkinson,  the  official 
gas  examiner  to  the  Sheffield  Corporation,  using  his  photo- 
metric and  gas-measuring  apparatus.  We  first  determined 
the'amount  of  light  radiated  by  a  single  fish-tail  gas-burner 
consuming  a  measured  quantity  of  gas  per  hour.  We  found 
when  another  was  placed  behind  this,  so  that  all  the  light 
of  the  second  had  to  pass  through  the  first,  that  the  light 
of  the  two  (measured  by  the  illuminating  intensity  of  their 
radiations  upon  a  screen  just  as  the  solar  luminosity  has 
been  measured)  was  just  double  that  of  one  flame,  three 
flames  (still  presenting  to  the  photometric  screen  only  the 
surface  of  one)  gave  it  three  times  the  amount  of  illumina- 
tion, and  so  on  with  any  number  of  flames  we  were  able  to 
test.  Mr.  Wilkinson  has  since  arranged  100  flames  on  the 
same  principle,  i.  e.,  so  that  the  99  hinder  flames  shall  all 
radiate  through  the  one  presented  to  the  screen,  thus  afford- 
ing the  same  surface  as  a  single  flame,  but  having  100  times 
its  thickness  or  depth,  and  he  finds  that  the  law  indicated 
by  our  first  experiments  is  fully  verified;  that  the  100 
flames  thus  arranged  illuminate  the  screen  100  times  as  in- 
tensely as  the  single  flame.  Other  modifications  of  these 
experiments,  described  in  Chapter  vii.  of  "  The  Fuel  of 
the  Sun,"  establish  the  principle  that  a  common  hydrocar- 
bon gas  flame  is  transparent  to  its  own  radiations,  or,  in 
other  words,  that  the  amount  of  light  radiated  from  such 
a  flame,  and  its  apparent  intensity  of  luminosity,  is  pro- 
portionate to  its  thickness;  therefore  the  luminosity  of  the 
sun  may  be  produced  by  a  photosphere  having  no  greater 
intrinsic  brilliancy  than  the  flame  of  a  tallow  candle,  pro- 
vided the  flame  is  of  sufficient  depth  or  thickness.  I  see 
good  reasons  for  inferring  that  its  intrinsic  brilliancy  is  less 
than  that  of  a  caudle — somewhere  between  that  and  a 
Bimsen's  burner. 

A  similar  series  of  experiments  upon  the  radiation  of  the 
heat  of  flames  through  each  other,  indicated  similar  results; 
but  my  apparatus  for  these  experiments  was  not  so  delicate 
and  reliable  as  in  the  experiments  on  light,  and,  therefore, 
I  cannot  so  decidedly  affirm  the  absolute  diathermancy  of 
flame  to  its  own  radiations.  Within  the  limits  of  error  of 


THE  FUEL  OF  THE  SUN.  23 

these  experiments,  I  found  that  with  the  same  radiant  sur- 
face presented  to  the  thermometer,  every  addition  to  the 
thickness  of  the  flame  produced  a  proportionate  increase  of 
radiation. 

This  important  law,  though  hitherto  unnoticed  by  philo- 
sophers, is  practically  understood  and  acted  upon  by  work- 
men who  are  engaged  in  furnace  operations.  Present  space 
will  not  permit  me  to  illustrate  this  by  examples,  but  in 
passing  I  may  mention  the  "mill  furnaces,"  where  armor- 
plates  and  other  large  masses  of  iron  are  raised  to  a  weld- 
ing temperature  by  radiant  heat,  and  the  ordinary  puddling 
furnace,  where  iron  is  melted  by  radiant  heat.  In  both  of 
these  special  arrangements  are  made  to  obtain  a  "body"  or 
thickness  of  radiant  flame,  while  intensity  of  combustion 
is  neglected  and  even  carefully  avoided. 

According  to  this  there  are  two  factors  engaged  in  pro- 
ducing the  radiant  effect  from  a  given  surface,  intensity^ 
and  quantity,  i.  e.,  brilliancy  and  thickness  in  the  case  of 
light,  and  temperature  and  thickness  in  the  case  of  heat. 
In  the  Bude  light,  for  example,  consisting  of  concentric 
rings  of  coal-gas,  we  have  small  intensity  with  great  quan- 
tity, in  the  lime-light  we  have  a  mere  surface  of  great  bril- 
liancy but  no  thickness.  If  I  am  right,  the  surface  of  the 
moon  maybe  brighter  than  the  luminous  surface  of  the  sun, 
the  peculiarities  of  moonlight  depending  upon  intensity, 
those  of  sunlight  upon  quantity  <3f  light. 

Thcflamo  that  roars  from  the  mouth  of  a  Bessemer  con- 
verter luis  but  small  intrinsic  brilliancy,  far  less  than  that 
of  fin  ordinary  gas  flnme,  as  may  be  seen  by  observing  the 
thin  waifs  that  sometimes  project  beyond  the  body  of  tho 
flame.  Nevertheless,  its  radiations  are  so  effective  that  it 
is  «i  painfully  dazzling  object  even  in  the  midst  of  sunny 
daylight;  but  then  we  have  here  not  a  holloAv  flame  fed  only 
by  outside  oxygen,  but  a  solid  body  of  flame  several  feet  in 
thickness.  Even  the  pallid  carbonic  acid  flame  which  ac- 
companies the  pouring  of  the  spiegeleisen  has  marvellous, 
illuminating  power. 

The  reader  will  now  be  able  to  understand  my  explana- 
tion of  the  sun-spots,  of  their  nucleus,  umbra,  and  penum- 
bra. From  what  I  have  stated  respecting  the  planetary 


24  SCIENCE  IN  SHORT  CUAPTERS. 

disturbances  or  the  solar  rotation,  the  photosphere  should 
present  all  the  appearances  due  to  the  movements  of  a  fiery 
ocean,  raging  and  seething  in  the  maddest  conceivable  fury 
of  perpetual  tempest.  If  the  surface  of  a  river  flowing 
peacefully  between  its  banks  is  perforated  with  conical  ed- 
dies whenever  it  meets  with  a  projecting  rock  or  obstacle, 
or  other  agency  which  disturbs  the  regularity  of  its  course, 
what  must  be  the  magnitude  of  the  eddies  in  this  ocean  of 
flame  and  heated  gases,  when  stirred  to  the  lowest  depths 
of  its  vast  profundity  by  the  irregular  reeling  of  the  solar 
nucleus  within?  Obviously,  nothing  less  than  the  sun- 
spots;  those  mighty  maelstroms  into  which  a  world  might 
be  dropped  like  a  pea  into  an  egg-cup. 

When  the  photosphere  or  shell  of  combining  gases  is 
thus  ripped  open,  the  telescopic  observer  looks  down  the 
vortex,  which,  if  deep  enough,  reveals  to  him  the  inner 
regions  of  dissociated  gases  and  vapors.  But  these  have 
the  opposite  property  to  that  which  I  have  shown  to  belong 
to  flame;  they  are  opaque  to  their  own  special  radiations, 
while  the  flame  is  transparent  to  the  light  of  the  inner 
portions  of  itself.  Thus,  the  dissociated  interior  of  the 
solar  envelope,  though  absolutely  white-hot,  will  be  com- 
paratively dark  (direct  experiment  has  proved  that  the 
darkness  of  the  spots  is  only  relative). 

The  sides  of  the  vortex  funnel  will  consist  of  a  mixture 
of  dissociated  gases,  flaming  gases,  and  combined  gases, 
and  will  thus  present  various  thicknesses  of  flame,  and 
thereby  display  the  various  shades  of  the  penumbra.  Space 
will  not  permit  me  here  to  follow  up  the  details  of  this 
subject,  as  I  have  done  in  the  original  work,  where  it  is 
shown  that  if  the  telescope  had  not  yet  been  invented,  all 
the  telescopic  details  of  spot  phenomena  might  have  been 
described  a  priori  as  necessary  consequences  of  the  consti- 
tution I  have  above  ascribed  to  the  sun. 

Not  merely  the  great  spot  phenomena,  but  all  the  minor 
irregularities  of  the  photosphere  follow  with  similarly  de- 
monstrable necessity.  Thus  the  many  interfering  solar 
tides  must  throw  up  great  waves,  literally  mountainous  in 
their  magnitude,  the  summits  and  ridges  of  which,  being 
raised  into  higher  regions  of  the  absorbing  vapordus  atnios- 


THE  FUEL  OF  THE  SUN.  25 

phere  that  envelopes  the  photosphere,  will  radiate  more 
freely,  its  dissociated  matter  will  combine  more  abundantly, 
and  will  thicken  the  photosphere  immediately  below;  this 
thicker  flame  will  be  more  luminous  than  the  normal  sur- 
face, and  thus  produce  the  phenomena  of  t\\e  faculcz. 

Besides  these  great  ground-swells  of  the  flaming  ocean  of 
the  photosphere,  there  must  be  lesser  billows,  and  ripples 
upon  these,  and  mountain  tongues  of  flame  all  over  the 
surface.  The  crests  of  these  waves,  and  the  summits  of 
these  flame-alps,  presenting  to  the  terrestrial  observer  a 
greater  depth  of  flaming  matter,  must  be  brighter  than  the 
hollows  and  valleys  between;  and  their  splendor  must  be 
further  increased  by  the  fact,  that  such  upper  ridges  and 
summits  are  less  deeply  immersed  in  the  outer  ocean  of 
absorbing  vapors,  which  limits  the  radiation  of  the  light' 
as  well  as  the  heat  of  the  photosphere.  The  effect  of  look- 
ing upon  the  surface  of  such  a  w'ild  fury  of  troubled  flame, 
with  its  confused  intermingling  of  gradations  of  luminosity, 
must  be  very  puzzling  and  difficult  to  describe;  and  hence 
the  "willow leaves,"  "rice grains,''  "mottling,"  "granules," 
"things,"  "flocculi,"  "bits  of  white  thread,"  "cumuli  of 
cotton  wool,"  "excessively  minute  fragments  of  porcelain," 
fc untidy  circular  masses,"  "ridges,"  "waves."  "hill 
knolls,"  etc.,  etc.,  to  which  the  luminous  irregularities  have 
been  compared. 

At  the  time  I  wrote,  the  means  of  examination  of  the 
edge  of  the  sun  by  the  spectroscope  was  but  newly  discov- 
ered, and  the  results  then  published  referred  chiefly  to  the 
prominences  proper.  Since  that,  a  new  term  has  been  in- 
troduced to  solar  technology,  the  "  sierra,"  and  the  observa- 
tions of  the  actual  appearances  of  this  sierra  precisely  cor- 
respond to  my  theoretical  description  of  the  limiting  surface 
of  the  photosphere,  which  was  written  before  I  was  ac- 
quainted with  these  observed  facts.  This  will  be  seen  by 
reference  to  Chapter  x.,  the  subject  of  which  is,  "The 
Varying  Splendor  of  Different  Portions  of  the  Photo- 
sphere. * 

*  Still  more  recently  (1882)  the  magnificent  photographs  of  Jannsen 
have  displayed  further  evidence  of  the  flame-tongue  character  of 
the  mottling. 


26  SCIENCE  IN  SHORT  CHAPTERS. 

But  I  must  not  linger  any  further  upon  this  part  of  the 
subject,  but  proceed  to  another,  where  subsequent  discov- 
eries have  strongly  confirmed  my  speculations. 

The  mean  specific  gravity  of  the  sun  is  not  quite  1£ 
times  that  of  water.  The  vapors  of  nickel,  cobalt,  copper, 
iron,  chromium,  manganese,  titanium,  zinc,  cadmium, 
aluminium,  magnesium,  barium,  strontium,  calcium,  and 
sodium,  have  been  shown  by  the  spectroscope  to  be  floating 
on  the  outer  regions  of  the  sun.  None  of  these  could  con- 
stitute the  body  of  the  sun  in  a  solid  or  liquid  state,  and 
be  subjected  to  the  enormous  pressure  which  such  a  mass 
must  exert  upon  itself  without  raising  the  mean  specific 
gravity  vastly  above  this ;  nor  is  there  any  other  kind  of 
matter  with'  which  we  are  acquainted  which  could  exist 
within  so  large  a  mass  in  a  liquid  or  solid  state,  and  retain 
so  low  a  density. 

I  must  confess  that  my  faith  in  the  logical  acumen  of 
mathematicians  has  been  rudely  shaken  by  the  manner  in 
which  eminent  astronomers  have  described  the  umbra  or 
nucleus  of  the  sun-spots  as  the  solid  body  of  the  sun  seen 
tnrough  his  luminous  atmosphere,  and  the  solid  surface  of 
Jupiter  seen  through  his  belts,  and  have  discussed  the 
habitability  of  Jupiter,  Saturn,  Uranus,  and  Neptune  al- 
ways on  the  assumption  of  their  solidiy,  while  the  specific- 
gravity  of  all  of  these  renders  this  surface  solidity  a  dem- 
onstrable physical  impossibility. 

If  the  sun  (or  either  of  these  planets)  has  a  solid  or  liq- 
uid nucleus,  it  must  be  a  mere  kernel  in  the  centre  of  a 
huge  orb  of  gaseous  matter,  and  though  I  have  spoken 
rather  definitely  of  the  solar  atmosphere  in  order  to  avoid 
complication,  1  must  not,  therefore,  be  understood  to  sup- 
pose that  there  exists  in  the  sun  any  such  definite  bound- 
ary to  the  base  of  the  atmospheric  matter  as  we  find  here 
on  the  earth.  The  temperature,  the  density,  and  all  we 
know  of  the  chemistry  of  the  sun  justify  the  conclusion 
that  in  its  outer  regions,  to  a  considerable  depth  below  the 
photosphere,  there  must  be  a  commingling  of  the  atmos- 
pheric matter  with  the  vapors  of  the  metals  whose  exist- 
ence the  spectroscope  has  revealed.  Some  of  these  must 
be  upheaved  together  with  the  dissociated  elements  of  wa- 


THE  FUEL   OF  THE  SUN.  27 

ter.  They  are  all  combustible,  and,  with  a  few  exceptions, 
the  products  of  their  combustion  would  solidify  after  they 
were  projected  beyond  the  photosphere.  Much  of  the  iron, 
nickel,  cobalt,  and  copper  might  pass  through  the  fiery  or- 
deal of  such  projection,  and  solidify  without  oxidation,  es- 
pecially when  more  or  less  enveloped  in  uncombiued  hy- 
drogen. 

It  is  obvious  that,  under  these  circumstances,  there  must 
occur  a  series  of  precipitations  analogous  to  those  from  the 
aqueous  vapor  of  our  atmosphere.  These  gaseous  metals, 
or  their  oxides,  must  be  condensed  as  clouds,  rain,  snow, 
and  hail,  according  to  their  boiling  and  metal  points,  and 
the  conditions  of  their  ejection.  We  know  that  sudden 
and  violent  atmospheric  disturbance,  accompanied  with 
fierce  electrical  discharges,  especially  favor  the  formation 
of  hailstones  in  our  terrestrial  atmosphere.  All  such  vio- 
lence must  be  displayed  on  a  hugely  exaggerated  scale  in 
the  solar  outbursts,  and  therefore  the  hailstone  formation 
should  preponderate,  especially  as  the  metallic  vnpors  con- 
dense more  rapidly  than  those  of  water  on  account  of  the 
much  smaller  amount  of  their  specific  heat,  and  of  the 
latent  heat  of  their  vapors. 

What  will  become  of  these  volleys  of  solid  matter  thus 
ejected  with  the  furious  and  protracted  explosions  forming 
the  solar  prominences  ?  In  order  to  answer  this  question, 
we  must  remember  that  the  spectroscope,  as  recently  ap- 
plied, merely  displays  the  gaseous,  chiefly  the  hydrogen, 
ejections ;  that  these  great  gaseous  flames  bear  a  similar 
relation  to  the  solid  projectiles  that  the  flash  of  a  gun  does 
to  the  grape-shot  or  cannon-ball.  Mr.  Lockyer  says  :  "In 
one  instance  I  saw  a  prominence  27,000  miles  high  change 
enormously  in  the  space  of  ten  minutes  ;  and,  lately,  I  have 
seen  prominences  much  higher  born  and  die  in  an  hour." 
He  has  recently  measured  an  actual  velocity  of  120  miles 
per  second  in  the  movements  of  this  gaseous  matter  of  the 
solar  eruptions,  the  initial  velocity  of  which  must  have  been 
much  greater.*  If  such  is  the  velocity  of  the  gaseous  ejec- 

*  Subsequent  observations  (1882)  by  Secchi,  Young,  and  others 
have  demonstrated  velocities  far  exceeding  this  ;  quite  sufficient  to 
project  the  solid  matter  clearly  beyond  the  sphere  of  solar  attraction. 


28  SCIENCE  IN  SHORT  CHAPTERS. 

tions,  what  must  be  that  of  the  solid  projectiles,  and  where 
must  they  go? 

A  cosmicai  cannonade  is  a  necessary  result  of  the  condi- 
tions I  have  sketched,  and  as  prominence-ejections  are  con- 
tinually in  progress,  there  must  be  a  continual  outpouring 
from  the  sun  of  solid  fragments,  which  must  be  flung  far 
beyond  the  limits  of  the  gaseous  prominences.  As  the 
luminosity  of  these  glowing  particles  must  be  very  small 
compared  with  that  of  the  photosphere,  they  will  be  in- 
visible in  the  glare  of  ordinary  sunshine  ;  but  if  our  eyes  be 
protected  from  this,  they  may  then  be  rendered  visible, 
both  by  their  own  glow  and  the  solar  light  they  are  capable 
of  reflecting.  They  should  be  seen  during  a  total  eclipse, 
and  should  exhibit  radiant  streams  proceeding  irregularly 
from  different  parts  of  the  sun,  but  most  abundantly  from 
the  neighborhood  of  the  spot  regions.  As  these  spot  re- 
gions occupy  the  intermediate  latitudes  between  the  poles 
and  the  equator  of  the  sun,  the  greatest  extensions  of  the 
outstreamiugs  should  be  N.E.  and  S.W.,  and  S.E.  and 
N.W.,  while  to  the  N.,  S.,  E.,  and  W.— that  is,  opposite 
the  poles  and  equator  of  the  sun — there  should  be  a  lesser 
extension.  The  result  of  this  must  be  an  approximation  to 
a  quadrilateral  figure,  the  diagonals  of  which  should  extend 
in  a  N.B.  and  S.W.,  and  a  S.E.  and  N.W.  direction,  or 
thereabouts.  I  say  "thereabouts,"  because  the  zone  of 
greatest  activity  is  not  exactly  intermediate  between  the 
poles  and  the  equator,  but  lies  nearer  to  the  solar  equa- 
tor. 

Examined  with  the  polariscope,  these  radiant  streams 
should  display  a  mixture  of  reflected  light  and  self-lumi- 
nosity. Examined  with  the  spectroscope,  a  faint  continu- 
ous spectrum  due  to  such  luminosity  of  solid  particles 
should  be  exhibited,  with  possibly  a  few  lines  due  to  the 
small  amount  of  vapor  which,  in  their  glowing  condition, 
they  might  still  give  off.  Besides  this,  there  should  appear 
the  spectroscope  indications  of  violent  electrical  discharges, 
which  must  occur  as  a  necessary  concomitant  of  the  furious 
ejections  of  aqueous  vapor  and  solid  particles.  All  these 
metallic  hailstones  must  be  highly  charged,  like  the  parti- 
cles of  vesicular  vapor  ejected  from  the  hydro-electric  ma- 


THE  FUEL  OF  THE  SUN.  29 

chine,  or  the  vapors  and  projectiles  of  a  terrestrial  volcanic 
eruption. 

I  need  scarcely  add  that  this  exactly  describes  the  actual- 
ly-observed results  of  the  recent  observations  on  the  corona, 
and  that  all  the  phenomena  of  this  great  solar  mystery  are 
but  necessary  and  predicable  results  of  the  constitution  I 
ascribe  to  the  sun. 

There  is  a  method  of  manufacturing  hypotheses  which 
has  become  rather  prevalent  of  late,  especially  among 
mathematicians,  who  take  observed  phenomena,  and  then 
arbitrarily  and  purely  from  the  raw  material  of  their  own 
imagination  construct  explanatory  atoms,  media,  and  ac- 
tions, which  are  shaved  and  pared,  scraped  and  patched, 
lengthened  and  shortened,  thickened  and  narrowed,  till 
they  are  made  to  fit  the  phenomena  with  mathematical  ac- 
curacy. These  laborious  creations  are  then  put  forth  as 
philosophical  truths,  and,  afterwards,  the  accuracy  of  their 
fitting  to  the  phenomena  is  quoted  as  evidence  of  the  posi- 
tive reality  of  the  ethers,  atoms,  undulations,  gyrations, 
collisions,  or  whatever  else  the  mathematician  may  huve 
thus  skilfully  created  and  fitted.  It  appears  to  me  that 
such  fitness  only  proves  the  ingenuity  of  the  fitter — the 
skill  of  the  mathematician — and  that  all  such  hypotheses 
belong  to  the  poetry  of  science;  they  should  be  distinctly 
labelled  as  products  of  mathematical  imagination,  and  no- 
wise be  confounded  with  objective  natural  truths.  Such 
products  of  the  imagination  of  the  expert  may  assist  the 
imagination  of  the  student  in  comprehending  some  phe- 
nomena, just  as  "Jack  Frost"  and  "Billy  Wind"  may 
represent  certain  natural  forces  to  babies ;  but  if  Jack 
Frost,  Billy  Wind,  electric  and  magnetic  fluids,  ultimate 
atoms,  interatomic  ethers,  nervous  fluids,  etc.,  are  allowed 
to  invade  the  intellect,  and  are  accepted  as  actual  physical 
existences,  they  become  very  mischievous  philosophical 
superstitions. 

I  make  this  digression  in  order  to  repudiate  any  partici- 
pation in  this  kind  of  speculation.  .Though  "The  Fuel  of 
the  Sun"  is  avowedly  a  very  bold  attempt  to  unravel  majestic 
mysteries,  I  have  not  sought  to  elucidate  the  known  by  means 
of  the  unknown,  as  do  these  inventors  of  imaginary  agents, 


30  SCIENCE  IN  SSOET  CHAPTERS. 

but  have  scrupulously  followed  the  opposite  principle.  I 
have  invented  nothing,  but  have  started  from  the  experi- 
mental facts  of  the  laboratory,  the  demonstrated  laws  of 
physical  action,  and  have  followed  up  step  by  step  what  I 
understand  to  be  the  necessary  consequences  of  these. 
Many  years  ago  I  convinced  myself  that  our  atmosphere  is 
but  a  portion  of  universal  atmospheric  matter ;  that  Dr. 
Wollaston  was  wrong,  and  that  the  compression  of  this 
universal  atmospheric  matter  is  possibly  the  source  of  solar 
light  and  heat ;  •  but  as  this  was  long  before  M.  Deville  had 
investigated  the  subject  of  dissociation  by  heat,*  I  was 
unable  to  work  out  the  problem  at  all  satisfactorily.  When 
I  subsequently  resumed  the  subject,  I  knew  nothing  about 
the  corona,  and  had  only  read  of  the  "  red  prominences"  as 
possible  lunar  appendages,  or  solar  clouds,  or  optical  illu- 
sions. I  had  worked  out  the  necessity  of  the  gaseous  erup- 
tions, and  their  action  in  effecting  an  interchange  of  solar 
and  general  atmospheric  matter,  as  the  means  of  maintain- 
ing the  solar  light  and  heat,  with  no  idea  of  proceeding 
further  with  the  problem,  when  the  announcement  that  the 
prominences  were  not  merely  unquestionable  solar  appen- 
dages, but  were  actually  upheaved  mountains  of  glowing 
hydrogen, suddenlyand  unexpectedly  suggested  their  identity 
with  my  required  atmospheric  upheavals.  It  is  true  that 
their  observed  magnitude  far  exceeded  my  theoretical  antici- 
pations, and  in  this  respect  I  have  made  some  a  posteriori 
adaptations,  especially  with  the  aid  of  a  clearer  understand- 
ing of  the  laws  of  dissociation  which  almost  simultaneously 
became  attainable. 

In  like  manner,  the  necessity  of  the  solid  ejections  pre- 
sented themselves  before  I  knew  anything  of  the  recently 
discovered  details  of  the  coronal  phenomena — when  I  had 
merely  read  of  a  luminous  halo  which  had  been  seen  around 
the  sun,  and  relying  upon  Mr.  Lockyer,  vaguely  supposed  it 
to  be  an  effect  of  atmospheric  illumination.  I  inferred  that 
streams  of  solid  particles  must  be  pouring  from  the  sun,  and 
showering  back  again,  but  had  no  idea  that  such  streams 

*My  first  memorandum  on  this  subject  is  dated  April  23,  1840,  in 
a  Register  of  Ideas,  then  commenced  hi  very  early  student  days. 


TEE  FUEL  OF  TEE  SUN.  31 

and  showers  were  actually  visible  until  I  was  rather  startled 
on  learning  that  the  corona,  instead  of  being,  as  I  had  loosely 
supposed,  a  mere  uniform  filmy  halo,  had  been  described  by 
Mr.  De  la  Kue,  in  his  Bakerian  Lecture  on  the  Eclipse 
of  1860,  as  "softening  off  with  very  irregular  outline,  and 
sending  off  some  long  streams,"  etc.  I  was  then  living  on 
the  sides  of  a  Welsh  mountain  far  away  from  public  libraries,  - 
and  being  no  astronomer,  my  own  books-  kept  me  better 
acquainted  with  the  current  progress  of 'experimental  than 
with  astronomical  science. 

Even  when  "  The  Fuel  of  the  Sun  "  was  published  I  knew 
nothing  of  the  American  observations  of  the  quadrangular 
figure  of  the  corona,  or  should  certainly  have  then  quoted 
them,  nor  of  the  fact  revealed  by  the  Eclipse  of  December, 
1870,  that,  "wherever  on  the  solar  disc  a  large  group  of 
prominences  was  seen  on  Mr.  Seabroke's  map,  there  a 
corresponding  bulging  out  of  the  corona  was  chronicled  on 
Professor  Watson's  drawing  ;  and  at  the  positions  where  no 
prominences  presented  themselves,  there  the  bright  portions 
of  the  corona  extended  to  the  smallest  distances  from  the 
sun's  limb  ;  and  that  Mr.  Brothers's  photographs  all  show 
the  corona  extending  much  further  towards  the  west  than 
towards  the  east,  the  west  being  "the  region  richest  in 
solar  prominences."  I  am  sorry  that  the  limits  of  this 
paper  will  not  permit  me  to  enter  more  fully  into  the 
bearings  of  the  recent  studies  of  the  corona  and  the  promi- 
nences upon  my  explanations  of  solar  phenomena,  especially 
as  the  differences  between  the  inner  and  outer  corona,  which 
still  appear  to  puzzle  astronomers,  are  exactly  what  my 
explanation  demands.  I  must  make  this  the  subject  of 
a  separate  paper,  and  proceed  at  once  to  the  next  step  of 
the  general  argument. 

Assuming  that  such  ejections  of  solid  matter  are  poured 
from  the  prominences,  to  what  distances  may  they  travel  ? 
lu  attempting  to  answer  this  question,  I  avowedly  ven- 
tured upon  dangerous  ground,  for  at  the  time  of  writing  I 
only  knew  that  the  force  of  upheaval  of  the  prominences 
must  be  enormous,  probably  sufficient  to  eject  solid  matter 
beyond  the  orbit  of  the  earth  and  even  beyond  that  of 
Mars.  Actual  measurements  of  the  eruptive  velocity  of 


32  SCIENCE  IN  SHORT  CHAPTERS. 

the  solar  prominences  have  since  been  made,  and  they  are 
so  great  as  to  relieve  me  of  my  quantitative  difficulty,  and 
show  that  I  was  quite  justified  in  the  bold  inference  that 
these  eruptions  may  account  for  the  zodiacal  light,  the 
zones  of  meteors  into  which  our  earth  is  sometimes  plunged, 
and  even  the  outer  zone  of  larger  bodies,  the  asteroids. 

But  how,  the  reader  will  ask,  can  such  solids,  ejected 
from  the  snn,  acquire  orbital  paths  around  him  "  We  have 
been  taught  that  the  parabola  is  the  necessary  path  of  such 
ejections."  Mr.  Proctor  has  evidently  reasoned  in  this 
manner,  for  in  last  April  number  of  "  Fraser's  Magazine" 
he  says  that  some  of  my  ideas  are  "  opposed  to  any  known 
laws,  physical  or  dynamical,"  that  "  there  is  nothing  abso- 
lutely incredible  in  the  conception  that  masses  of  gaseous, 
liquid,  or  solid  matter  should  be  flung  to  a  height  exceeding 
manifold  that  of  the  loftiest  of  the  colored  prominences; 
whereas  it  is  not  only  incredible,  but  impossible,  that  such 
matter  should  in  any  case  come  to  circle  in  a  closed  orbit 
round  the  sun." 

More  careful  reading  would  have  shown  Mr.  Proctor  that 
I  have  considered  other  conditions  besides  those  of  the  text- 
books, that  the  case  is  by  no  means  one  of  simple  radial 
projection  from  a  fixed  body  into  free  space  and  undis- 
turbed return.  I  distinctly  stated  that  "  the  recent  ejections 
may  have  any  form  of  orbit  within  the  boundaries  of  the 
conic  sections,"  from  a  straight  line  returning  upon  itself, 
due  to  absolutely  vertical  projection,  to  a  circular  orbit  pro- 
duced by  the  tangential  projection  of  such  curving  promi- 
nences as  the  ram's  horn,  etc.  The  outline  of  the  zodiacal 
light  would  be  formed  by  the  termination  or  aphelion  portion 
of  these  excursions,  or  of  such  a  number  of  them  as  should 
be  sufficient  to  produce  a  visible  result. 

Again,  speaking  of  the  asteroids,  in  Chapter  xiv.,  I 
state  that  "I  should  have  expected  a  still  greater  elonga- 
tion and  eccentricity  in  some  of  them,  and  such  orbits  may 
have  existed  ;  but  an  asteroid  with  an  orbit  of  cometary 
eccentricity  that  would  in  the  course  of  each  revolution 
cross  the  paths  of  Mercury,  Venus,  the  Earth,  and  Mars  in 
nearly  the  same  plane,  and  dive  through  the  thickly  scat- 
tered zodiacal  cluster,  both  in  going  to  the  sun  and  return- 


THE  FUEL   OF  THE  SUN.  33 

ing  from  it,  would  be  subject  to  disturbances  which  would 
continue  until  one  of  two  things  occurred.  "  Its  tangential 
force  might  become  so  far  neutralized  and  its  orbit  so  much 
elongated,  that  finally  its  perihelion  distance  should  not 
exceed  the  solar  radius,  when  it  would  finish  its  course  by 
returning  to  the  sun.  On  the  other  hand,  its  tangential 
velocity  might  be  increased  by  heavy  pulls  from  Jupiter, 
when  slowly  turning  its  aphelion  path,  and  be  similarly  in- 
fluenced by  friendly  jerks  in  crossing  the  orbits  of  the  in- 
ferior planets ;  and  thus  its  orbit  might  be  widened,  until  it 
ceased  periodically  to  cross  the  path  of  any  of  the  planets 
by  establishing  itself  in  an  orbit  constantly  intermediate 
between  any  two.  Having  once  settled  into  such  a  path, 
it  would  remain  there  with  comparative  stability  and  per- 
manency. If  I  am  right  in  this  view  of  the  dynamical  his- 
tory of  these  older  ejections,  all  the  long  elliptical  paths  of 
zodiacal  particles,  meteorites,  or  asteroids,  would  thus  in 
the  course  of  ages  become  eliminated,  and  the  remaining 
orbits  "would  be  of  planetary  rather  than  cometary  propor- 
tions." 

A  little  reflection  on  the  above-stated  laws  of  dissociation 
will  show  that  the  maximum  violence  of  hydrogen  explo- 
sion will  not  occur  at  the  birth  of  the  ejections,  but  after- 
wards, when  the  dissociated  gases  have  been  already  hurled 
beyond  the  sphere  of  restraining  vapors.  If  my  explana- 
tion is  correct,  the  typical  form  of  a  solar  prominence  should 
be  that  of  a  spreading  tree  with  a  tall  stem.  At  first  the 
least  resistance  to  radiation  and  consequent  explosive  com- 
bination must  be  in  the  vertical  direction,  as  this  will  afford 
the  shortest  line  that  can  be  drawn  through  the  thickness 
of  the  surrounding  jacket  of  resisting  vapor;  but  when 
raised  above  this  envelope,  the  dissociated  gases,  cooled  by 
their  own  expansion  and  comparatively  free  to  radiate  in 
all  directions  except  downwards,  will  explode  laterally  as 
well  as  vertically,  and  thus  spread  out  into  a  head.  My 
theoretical  prominence  will  be,  in  short,  a  monster  rocket 
proceeding  steadily  upwards  to  a  certain  extent,  and  then 
gradually  bursting  and  projecting  its  missiles  in  every  di- 
rection from  the  vertical  to  the  absolutely  horizontal. 
Should  the  latter  acquire  a  velocity  of  about  300  miles  per 


34  SCIENCE  IN  SHORT  CHAPTERS. 

second,  not  merely  a  closed  but  even  an  absolutely  circular 
orbit  would  be  possible.  These  and  the  multitude  of  weaker 
lateral  ejections,  reaching  the  sun  by  short  parabolic  paths, 
explain  the  mystery  of  the  inner  corona. 

I  need  only  refer  Mr.  Proctor  to  his  own  recently  pub- 
lished book  on  the  Sun,  where  he  will  find  on  plates  4,  5, 
and  6  a  number  of  drawings  from  Zollner  and  Respighi, 
which  so  thoroughly  confirm  my  necessary  theoretical  de- 
ductions that  they  might  be  a  series  of  fancy  sketches  of 
my  own.  When  we  consider  that  the  base  of  a  prominence 
is  only  visible  when  it  happens  to  start  exactly  from  the 
limb  of  the  sun,  while  the  vastly  greater  proportion  of  those 
which  are  observed,  and  have  been  drawn,  have  much  of 
the  stem  cut  off  from  view  by  the  solar  rotundity,  the  evi- 
dence afforded  by  such  drawings  in  support  of  my  the- 
oretical deduction,  that  the  typical  form  of  the  solar  promi- 
nences is  that  of  a  palm-tree  or  bursting  rocket,  is  greatly 
strengthened.* 

In  a  paper  by  P.  Secchi,  dated  Rome,  March  20,  1871, 
and  published  in  the  "  Comptes  Rendus,"  March  27,  this 
veteran  solar  observer  speaks  of  the  prominences  as  com- 
posed of  jets,  which,  "upon  reaching  a  certain  elevation, 
stop  and  whirl  upon  themselves,  giving  birth  to  a  brilliant 
cloud."  This  cloud  is  represented  as  spreading  out  on  all 
sides  from  the  summit  of  the  combined  jets.  Again  he 
says,  "It  is  very  common  to  see  a  litte  jet  spot  at  a  certain 
elevation  above  the  chromosphere,  and  there  spread  itself 
out  into  &ivi'de  hat  ("  un  large  cha-peau")  of  an  absolutely 
nebulous  constitution."  This  outspreading  nebulosity  is 
the  flash  of  the  incandescent  vapors  produced  by  the  ex- 
plosion which  is  theoretically  demanded  by  my  explanation 
to  occur  exactly  in  the  manner  and  place  described.  These 
expanded  incandescent  gases  will  be  rendered  visible  by 

*  Any  reader  of  ' '  The  Fuel  of  the  Sun"  will  perceive  that  the  vapor- 
ous envelope  which  I  have  described  as  "an  effectual  jacket  for  limit- 
ing the  amount  of  radiation,"  is  a  complete  theoretical  anticipation 
and  explanation  of  the  "solar  crust"  of  Respighi  and  the  "Tren- 
nungschicht"  of  Zollner.  We  agree  perfectly  in  our  conclusions, 
though  arriving  at  them  by  such  very  different  paths,  and  so  inde- 
pendently of  each  other. 


THE  FUEL   OF  THE  SUN.  35 

the  spectroscopic  dilution  of  the  continuous  spectrum  of  the 
denser  photosphere,  while  the  solid  projectiles  that  must 
proceed  from  them  in  every  direction  can  only  be  seen  dur- 
ing a  solar  eclipse. 

The  observations  and  drawings  of  Zollner  and  Kespighi 
were,  for  the  most  part,  made  while  my  book  was  in  the 
press,  and,  like  those  of  Secchi  above  quoted,  were  un- 
known to  me  when  I  wrote;  I  was  then  only  able  to  quote, 
in  support  of  my  theoretical  requirements,  the  evidences  of 
actually  observed  tangential  ejection  afforded  by  Sir  John 
HerschePs  account  of  the  great  solar  storm  of  September  1, 
1859. 

Besides  this  direct  tangential  projection  there  are  other 
elements  of  motion  contributing  to  the  same  result,  such  as 
the  whirl  of  the  prominences  on  themselves,  their  motion 
of  translation  on  the  sun's  disk,  and  the  rotation  of  the  sun 
itself. 

I  must  now  bring  this  sketch  to  a  close  by  stating  that, 
in  order  to  submit  the  fundamental  question  of  an  universal 
atmosphere  to  an  experimentumcrucis  analogous  to  that  by 
which  Pascal  tested  the  atmospheric  theory  of  Torricelli,  I 
have  calculated  the  theoretical  density  of  the  atmosphere  of 
the  moon  and  of  each  of  the  planets,  and  compared  the 
results  as  severely  as  I  could  with  the  observed  facts.  As 
Jupiter  is  27,100  times  heavier  than  the  moon,  and  between 
these  wide  extremes  there  are  six  planets  presenting  great 
variations  of  mass,  the  probabilities  of  accidental  coinci- 
dence are  overwhelmingly  against  me,  and  a  close  concur- 
rence of  observed  telescopic  refraction  and  other  phenom- 
ena with  the  theoretical  atmospheric  density  must  afford 
the  strongest  possible  confirmation  of  the  soundness  of  the 
basis  of  my  whole  argument.  Such  a  concurrence  exists, 
and  some  new  and  very  curious  light  is  unexpectedly  thrown 
upon  the  meteorology  of  Mars  and  the  constitution  of  the 
larger  planets.  The  latter,  if  I  am  right,  must  be  minia- 
ture suns,  permanently  red  or  white-hot,  must  be  some- 
thing like  a  photosphere,  surrounded  by  a  sphere  of  vapor 
(the  outside  of  which  we  see),  must  have  mimic  spot  vor- 
tices and  prominences,  and  in  the  case  of  Saturn  must 
eject  volle}rs  of  meteoric  matter,  some  of  which  should 


36  SCIENCE  IN  SHORT  CHAPTERS. 

finally  settle  down  into  orbital  paths,  and  thus  produce  the 
rings. 

These  are  startling  conclusions,  and  when  I  reached  them 
they  were  utterly  at  variance  with  general  astronomical 
opinion,  but  I  find  since  their  publication  that  some  astro- 
nomers have  already  shown  considerable  readiness  to  adopt 
them.  In  my  case  this  view  of  the  solar  constitution  of  the 
larger  planets  is  not  a  matter  of  mere  opinion,  or  guessing, 
or  probability,  but  it  follows  of  necessity,  and  as  stated  on 
page  200,  "  the  great  mystery  of  Saturn's  rings  is  resolved 
into  a  simple  consequence,  a  demonstrable  and  necessary 
result  of  the  operation  of  the  familiar  forces,  whose  laws  of 
action  have  been  demonstrated  here  upon  the  earth  by  ex- 
perimental investigation  in  our  laboratories.  No  strained 
hypotheses  of  imaginary  forces  are  required,  no  ethers  or 
other  materials  are  demanded,  beyond  those  which  are 
beneath  our  feet  and  around  our  heads  here  upon  our  own 
planet;  all  that  is  necessary  is  to  grant  that  the  well-known 
elements  and  compounds  of  the  chemist,  and  the  demon- 
strated forces  of  the  experimental  physicist,  exist  and  ope- 
rate in  the  places,  and  have  the  quantities  and  modes  of 
distribution  described  by  the  astronomer;  this  simple  postu- 
late admitted,  these  wondrous  appendages  spring  into 
rational  existence,  and  like  the  eternal  fires  of  the  sun,  the 
barren  surface  of  the  moon,  the  dry  valleys  of  Mercury,  the 
hazy  equivocations  of  Venus,  the  seas  and  continents  and 
polar  glaciers  of  Mars,  and  the  cloud-covered  face  Jupiter, 
follow  as  necessary  consequences  of  an  universal  atmos- 
phere." 

If  I  am  right  in  ascribing  a  gaseous  condition  to  the  sun 
and  the  larger  planets,  and  tracing  the  maintenance  of  this 
condition  to  the  disturbing  gravition  of  the  attendant 
planets  or  satellites,  a  solution  of  the  riddle  of  the  nebulse 
at  once  presents  itself.  We  have  only  to  suppose  a  star 
cluster  or  group  composed  of  orbs  of  solar  or  great  planetary 
dimensions,  and  that  these  act  mutually  upon  each  other 
as  the  planets  on  our  sun,  or  the  satellites  upon  Saturn, 
but  in  a  far  more  violent  degree  owing  to  the  far  greater 
relative  masses  of  the  reacting  elements,  and  we  obtain  the 
conditions  under  which  great  gaseous  orbs  would  be  not 


THE  FUEL  OF  THE  SUN.  37 

merely  pitted  on  their  surface,  but  riven  to  their  very  cen- 
tres, moulded  and  shaped  throughout  by  the  whirling  hur- 
ricane of  their  whole  substance.  When  thus  in  the  centre 
of  a  tornado  of  opposing  gravitations  the  tortured  orb  would 
be  twisted  bodily  into  a  huge  vorticose  crater,  into  the 
bowels  of  which  the  aqueous  vapor  would  be  dragged  and 
dissociated,  and  then,  entangled  with  the  inner  matter  of 
the  riven  sphere,  would  be  hurled  upwards,  again  to  burst 
forth  in  an  explosion  of  such  magnitude  that  the  original 
body  would  be  measurably  presented  as  a  mere  appendage, 
the  rocket  case  of  the  flood  of  fire  it  had  vomited  forth. 

The  reader  must  complete  the  picture.  If  he  will  take 
a  little  trouble  in  doing  so  he  will  find  that  it  becomes  a 
portrait  of  one  or  the  other  of  the  nebulas,  according  to  the 
kind  of  intergravitating  star-cluster  from  which  he  starts. 
I  have  endeavored  to  work  out  some  of  the  details  of  the 
nebular  conditions  in  Chapter  xx.  In  Chapter  xxi.  I  have 
concluded  by  showing  the  analogy  between  a  sun  and  the 
hydro-electric  machine,  the  sun  being  the  cylinder  and  the 
prominences  the  steam  jets.  If  issuing  jets  of  high-pres- 
sure steam  have  the  same  properties  at  a  distance  of  93 
millions  of  miles  from  the  earth  as  upon  its  surface,  the 
body  of  the  sun  and  the  issuing  steam  must  be  in  opposite 
electrical  conditions,  and  furious  electrical  excitation  must 
result;  and  if  the  laws  of  electrical  induction  are  constant 
throughout  the  universe,  the  earth  must  be  as  necessarily 
subject  to  solar  electrical  influence  as  to  his  thermal  radia- 
tions. Thus  the  same  reasoning  which  explains  the  origin 
and  maintenance  of  the  solar  heat  and  light,  the  sun-spots, 
the  photosphere,  the  chromosphere,  the  sierra,  the  promi- 
nences, the  zodiacal  light,  the  aerolites  and  asteroids;  the 
meteorology  of  the  planets  and  the  rings  of  Saturn,  also 
shows  how  the  electrical  disturbances  which  produce  the 
aurora  borealis  and  direct  the  needle  may  originate. 

Electrical  theories  of  the  corona  and  zodiacal  light,  and 
their  connection  of  some  kind  with  the  aurora  borealis, 
have  been  put  forth  in  many  shapes,  but  so  far  as  I  have 
learned  none  afford  any  explanation  of  the  origin  of  the 
electrical  disturbance.  Without  this  they  are  like  the  vor- 
tices of  Descartes,  which  explained  the  movements  of  the 


38  SCIENCE  IN  SHORT  CHAPTERS. 

planets  by  supposing  another  kind  of  motion  still  more 
incomprehensible. 

Explanations  which  are  more  difficult  to  explain  than 
the  phenomena  they  propose  to  elucidate  only  obscure  the 
light  of  true  science,  and  stand  as  impedimente  to  the  pro- 
gress of  sound  philosophy. 


DR.  SIEMENS'  THEORY  OF  THE  SUN. 

A  PAPER  was  read  on  March  2,  1882,  by  Dr.  0.  W.  Sie- 
mens at  the  Royal  Society,  and  he  published  an  article  on 
"A  New  Theory  of  the  Sun"  in  the  April  number  of  the 
Nineteenth  Century.  All  who  have  read  my  essay  on  "  The 
Fuel  of  the  Sun"  are  surprised  at  the  statement  with  which 
the  magazine  article  opens,  yiz. :  that  this  "  maybe  termed 
a  first  attempt  to  open  for  the  sun  a  debtor  and  creditor 
account,  inasmuch  as  he  has  hitherto  been  regarded  only  as 
a  great  almoner  pouring  forth  incessantly  his  boundless 
wealth  of  heat,  without  receiving  any  of  it  back." 

Some  of  my  friends  suppose  that  Dr.  Siemens  has  wilfully 
ignored  the  most  important  element  of  my  theory,  and  have 
suggested  indignation  and  protest  on  my  part.  I  am  quite 
satisfied,  however,  that  they  are  mistaken.  I  see  plainly 
enough  that  although  Dr.  Siemens  quotes  my  book,  he  had 
not  read  it  when  he  did  so;  that  in  stating  that  "  Grove, 
Humboldt,  Zoelluer,  and  Mattieu  Williams  have  boldly  as- 
serted the  existence  of  a  space  filled  with  matter,"  lie  de- 
rived this  information  from  the  paper  of  Dr.  S terry  Hunt 
which  he  afterward  quotes.  This  inference  has  been  con- 
firmed by  subsequent  correspondence  with  Dr.  Siemens, 
who  tells  me  that  he  saw  the  book  some  years  since  but  had 
not  read  it.  My  contributions  to  the  philosophy  of  solar 
physics  would  have  been  far  more  widely  known  and  better 
appreciated  had  I  followed  the  usual  course  of  announcing 
firstly  "a  working  hypothesis,"  to  warn  others  off  the 
ground,  then  reading  a  preliminary  paper,  then  another  and 
another,  and' so  on  during  ten  or  a  dozen  years,  instead  of 


DR.    SIEMENS'   THEORY  OF  TEE  SUN.  39 

publishing  all  at  once  an  octavo  volume  of  240  pages,  which 
has  proved  too  formidable  even  to  many  of  those  who  arc 
specially  interested  in  the  subject. 

I  am  compelled  to  infer  that  this  is  the  reason  why  so 
many  of  the  speculations,  which  were  physical  heresies 
when  expounded  therein,  have  since  become  so  generally 
adopted,  without  corresponding  acknowledgment.  This  is 
not  the  place  for  specifying  the  particulars  of  such  adop- 
tions, but  I  may  mention  that  in  due  time  "An  Appendix 
to  the  Fuel  of  the  Sun,"  including  the  whole  history  of  the 
subject,  will  be  published.  The  materials  are  all  in  hand, 
and  only  await  arrangement.  In  the  meantime  I  will 
briefly  state  some  of  the  points  of  agreement  and  difference 
between  Dr.  Siemens  and  myself. 

In  the  first  place,  we  both  take  as  our  fundamental  basis 
of  speculation  the  idea  of  an  universal  extension  of  atmos- 
pheric matter,  and  we  both  regard  this  as  the  recipient  of 
the  diffused  solar  radiations,  which  are  afterwards  recovered 
and  recondensed,  or  concentrated.  Thus  our  "  fuel  of  the 
sun"  is  primarily  the  same,  but,  as  will  presently  be  seen, 
our  machinery  for  feeding  the  solar  furnace  is  essentially 
different. 

Certain  desiccated  pedants  have  sneered  at  my  title,  "The 
Fuel  of  the  Sun,"  as  "  sensational,"  and  have  refused  to 
read  the  book  on  this  account;  but  Dr.  Sterry  Hunt  has 
provided  me  with  ample  revenge.  He  has  disentombed  an 
interesting  paper  by  Sir  Isaac  Newton,  dated  1675,  in  which 
the  same  sensationalism  is  perpetrated  with  very  small  mo- 
dification, Sir  Isaac  Newton's  title  being  "  Solary  Fuel." 
Besides  this,  his  speculations  are  curiously  similar  to  my 
own,  his  fundamental  idea  being  evidently  the  same,  but 
the  chemistry  of  his  time  was  too  vague  and  obscure  to  ren- 
der its  development  possible.  This  paper  was  neglected 
and  set  aside,  was  not  printed  in  the  Transactions  of  the 
Eoyal  Society,  and  remained  generally  unknown  till  a  few 
months  ago,  when  the  energetic  American  philosopher 
brought  it  forth,  and  discussed  its  remarkable  anticipations. 

Dr.  Siemens  supposes  that  the  rotation  of  the  sun  effects 
a  sort  of  "fan  action," by  throwing  off  heated  atmospheric 
matter  from  his  equatorial  regions,  which  atmospheric 


40  SCIENCE  IN  SHORT  CHAPTERS. 

matter  is  afterwards  reclaimed  and  passed  over  to  the  polar 
regions  of  the  sun.  This  interchange  he  describes  as 
effected  by  the  differences  of  pressure  on  the  fluid  envelope 
of  the  sun;  the  portion  over  the  polar  regions  being  held 
down  by  the  whole  force  of  solar  gravitation,  while  the 
equatorial  atmosphere  is  subject  to  this  pressure,  or  attrac- 
tion, minus  the  centrifugal  impulse  due  to  solar  rotation. 
He  maintains  that  this  "centrifugal  action,  however  small 
in  amount  as  compared  with  the  enormous  attraction  of  the 
sun,  would  destroy  the  balance,  and  determine  a  motion 
towards  the  sun  as  regards  the  mass  opposite  the  polar 
surface,  and  into  space  as  regards  the  equatorial  mass." 
He  adds  that  "the  equatorial  current  so  produced,  owing 
to  its  mighty  proportions,  would  flow  outwards  into  space, 
to  a  practically  unlimited  distance." 

I  will  not  here  discuss  the  dynamics  of  this  hypothesis  ; 
whether  the  reclaiming  action  of  the  superior  polar  attrac- 
tion would  occur  at  the  vast  distances  from  the  sun  supposed 
by  Dr.  Siemens,  or  much  nearer  home,  and  produce  an 
effect  like  the  recurving  of  the  flame  of  his  own  regenera- 
tive gas-burner ;  or,  whether  he  is  right  in  comparing  the 
centrifugal  force  at  the  solar  equator  with  that  of  the  earth, 
by  simply  measuring  the  relative  velocity  of  translation  irre- 
spective of  angular  velocity.  I  will  merely  suggest  that  in 
discussing  these,  it  is  necessary,  in  order  to  do  justice  to 
Dr.  Siemens,  to  always  keep  in  mind  the  assumed  condition 
of  an  universal  and  continuous  atmospheric  medium,  and 
not  to  reason,  as  some  have  done  already,  upon  the  basis  of 
a  limited  solar  atmosphere  with  a  definite  boundary,  from 
beyond  which  particles  of  atmospheric  matter  are  to  be 
flung  away  into  vacuous  space,  without  the  intervention  of 
all-pervading  fluid  pressure. 

It  is  evident  that  if  such  fan  action  can  bring  back  all 
the  material  that  has  received  the  solar  radiations,  and  which 
holds  them  either  as  temperature  or  otherwise,  the  restora- 
tion and  perpetuation  of  solar  energy  will  be  complete,  for 
even  the  heat  received  by  our  earth  and  its  brother  and 
sister  planets  would  still  remain  in  the  family,  as  they  would 
radiate  it  into  the  interplanetary  atmospheric  matter  sup- 
posed to  be  reclaimed  by  the  sun. 


WOKL,D  DOW  a  tiJSHJZ.  41 

But,  as  Mr.  Proctor  has  clearly  shown,  the  rays  of  the 
sun  cannot  do  all  the  work  thus  required  for  his  own  restora- 
tion without  becoming  extinguished  as  regards  the  outside 
universe  ;  and  if  the  other  suns — i.e.,  the  stars — do  the  same 
they  could  not  be  visible  to  us. 

Thus  Dr.  Siemens'  theory  removes  our  sun  from  his 
place  among  the  stars,  and  renders  the  great  problem  of 
stellar  radiation  more  inscrutable  than  ever  by  thus  putting 
the  evidence  of  our  great  luminary  altogether  out  of  court, 

My  theory,  on  the  contrary,  demands  only  a  gradual  ab- 
sorption of  solar  and  stellar  rays,  such  as  actual  observation 
of  their  varying  splendor  indicates. 

If  space  were  absolutely  transparent,  and  its  infinite 
depths  peopled  throughout,  the  firmament  would  present  to 
our  view  one  continuous  blazing  dome,  as  all  the  spaces 
between  the  nearer  stars  would  be  filled  by  the  infinity  of 
radiations  from  the  more  distant. 


ANOTHER  WOKLD  DOWN  HEBE. 

WHAT  a  horrible  place  must  this  world  appear  when  re- 
garded according  to  our  ideas  from  an  insect's  point  of  view! 
The  air  infested  with  huge  flying  hungry  dragons,  whose 
gaping  and  snapping  mouths  are  ever  intent  upon  swallow- 
ing the  innocent  creatures  for  whom,  according  to  the  in- 
sect, if  he  were  like  us,  a  properly  constructed  world  ought 
to  be  exclusively  adapted.  The  solid  earth  continually 
shaken  by  the  approaching  tread  of  hideous  giants — mov- 
ing mountains — that  crush  out  precious  lives  at  every  foot- 
step, an  occasional  draught  of  the  blood  of  these  monsters, 
stolen  at  life-risk,  affording  but  poor  compensation  for  such 
fatal  persecution. 

Let  us  hope  that  the  little  victims  are  less  like  ourselves 
than  the  doings  of  ants  and  bees  might  lead  us  to  suppose ; 
that  their  mental  anxieties  are  not  proportionate  to  the 
optical  vigilance  indicated  by  the  four  thousand  eye-lenses 
of  the  common  house-fly,  the  seventeen  thousand  of  the 


42  SCIENCE  IN  SHORT  CHAPTERS. 

cabbage  butterfly  and  the  wide-awake  dragon-fly,  or  the 
twenty-five  thousand  possessed  by  certain  species  of  still 
more  Vigilant  beetles. 

Each  of  these  little  eyes  has  its  own  cornea,  its  lens,  and 
a  curious  six-sided,  transparent  prism,  at  the  back  of  which 
is  a  special  retina  spreading  out  from  a  branch  of  the  main 
optic  nerve,  which,  in  the  cockchafer  and  some  other  crea- 
tures, is  half  as  large  as  the  brain.  If  each  of  these  lenses 
forms  a  separate  picture  of  each  object  rather  than  a  single 
mosaic  picture,  as  some  anatomists  suppose,  what  an  awful 
army  of  cruel  giants  must  the  cockchafer  behold  when  he 
is  captured  by  a  schoolboy! 

The  insect  must  see  a  whole  world  of  wonders  of  which 
we  know  little  or  nothing.  True,  we  have  microscopes, 
with  which  we  can  see  one  thing  at  a  time  if  carefully  laid 
upon  the  stage  ;  but  what  is  the  finest  instrument  that  Koss 
can  produce  compared  to  that  with  twenty-five  thousand 
object-glasses,  all  of  them  probably  achromatic,  and  each 
one  a  living  instrument,  with  its  own  nerve-branch  supply- 
ing a  separate  sensation?  To  creatures  thus  endowed  with 
microscopic  vision,  a  cloud  of  sandy  dust  must  appear  like 
an  avalanche  of  massive  rock-fragments,  and  everything 
else  proportionally  monstrous. 

One  of  the  many  delusions  engendered  by  our  human 
self-conceit  and  habit  of  considering  the  world  as  only  such 
as  we  know  it  from  our  human  point  of  view,  is  that  of  sup- 
posing human  intelligence  to  be  the  only  kind  of  intelli- 
gence in  existence.  The  fact  is,  that  what  we  call  the 
lower  animals  have  special  intelligence  of  their  own  as  far 
transcending  our  intelligence  as  our  peculiar  reasoning  in- 
telligence exceeds  theirs.  We  are  as  incapable  of  following 
the  track  of  a  friend  by  the  smell  of  his  footsteps  as  a  dog 
is  of  writing  a  metaphysical  treatise. 

So  with  insects.  They  are  probably  acquainted  with  a 
whole  world  of  physical  facts  of  which  we  are  utterly  igno- 
rant. Our  auditory  apparatus  supplies  us  with  a  knowl- 
edge ef  sounds.  What  are  these  sounds?  They  are  vibra- 
tions of  matter  which  are  capable  of  producing  corresponding 
or  sympathetic  vibrations  of  the  drums  of  our  ears  or  the 
bones  of  our  skull,  When  we  carefully  examine  the  sub- 


ANOTHER  WORLD  DOWN  HERE.  43 

ject,  and  count  the  number  of  vibrations  that  produce  our 
world  of  sounds  of  varying  pitch,  we  find  that  the  human 
ear  can  only  respond  to  a  limited  range  of  such  vibrations. 
If  they  exceed  three  thousand  per  second,  the  sound  be- 
comes too  shrill  for  average  people  to  hear  it,  though  some 
exceptional  ears  can  take  up  pulsations  or  waves  that  suc- 
ceed each  other  more  rapidly  than  this. 

Seasoning  from  the  analogy  of  stretched  strings  and 
membranes,  and  of  air  vibrating  in  tubes,  etc.,  we  are  justi- 
fied in  concluding  that  the  smaller  the  drum  or  the  tube  the 
higher  will  be  the  note  it  produces  when  agitated,  and  the 
smaller  and  the  more  rapid  the  aerial  wave  to  which  it  will 
respond.  The  drums  of  insect  ears,  and  the  tubes,  etc., 
connected  with  them,  are  so  minute  that  their  world  of 
sounds  probably  begins  where  ours  ceases  ;  that  the  sound 
which  appears  to  us  as  continuous  is  to  them  a  series  of  sep- 
arated blows,  just  as  vibrations  of  ten  to  twelve  per  second 
appear  to  us.  We  begin  to  hear  such  vibrations  as  contin- 
uous sounds  when  they  amount  to  about  thirty  per  second. 
The  insect's  continuous  sound  probably  begins  beyond  three 
thousand.  The  blue-bottle  may  thus  enjoy  a  whole  world 
of  exquisite  music  of  which  we  know  nothing. 

There  is  another  very  suggestive  peculiarity  in  the  aud- 
tory  apparatus  of  insects.  Its  structure  and  position  are 
something  between  those  of  an  ear  and  of  an  eye.  Careful 
examination  of  the  head  of  one  of  our  domestic  compan- 
ions— the  common  cockroach  or  black-beetle — will  reveal 
two  round  white  points,  somewhat  higher  than  the  base  of 
the  long  outer  antennse,  and  a  little  nearer  to  the  middle 
line  of  the  head.  These  white  projecting  spots  are  formed 
by  the  outer  transparent  membrane  of  a  bag  or  ball  filled 
with  fluid,  which  ball  or  bag  rests  inside  another  cavity  in 
the  head.  It  resembles  our  own  eye  in  having  this  exter- 
nal transparent  tough  membrane,  which  corresponds  to  the 
cornea  or  transparent  membrane  forming  the  glass  of  our 
eye-window  ;  which,  like  the  cornea,  is  backed  by  the  fluid 
in  an  ear-ball  corresponding  to  our  eye-ball,  and  the  back 
of  this  ear-ball  appears  to  receive  the  outspread  ings  of  a 
nerve,  just  as  the  back  of  our  eye  is  lined  with  that  out- 
spread of  the  optic  nerve  forming  the  retina.  There  does 


44  SCIENCE  IN  SHORT  CHAPTERS. 

not  appear  to  be  in  this  or  other  insects  a  tightly  stretched 
membrane  which,  like  the  membrane  of  our  ear-drum,  is 
fitted  to  take  up  bodily  air- waves  and  vibrate  responsively 
to  them.  But  it  is  evidently  adapted  to  receive  and  con- 
centrate some  kind  of  vibration,  or  motion,  or  tremor. 

What  kind  of  motion  can  this  be?  What  kind  of  per- 
ception does  this  curious  organ  supply?  To  answer  these 
questions  we  must  travel  beyond  the  strict  limits  of  scien- 
tific induction  and  enter  the  fairyland  of  scientific  imagi- 
nation. We  may  wander  here  in  safety,  provided  we  al- 
ways remember  where  we  are,  and  keep  a  true  course  guided 
by  the  compass-needle  of  demonstrable  facts. 

I  have  said  that  the  cornea-like  membrane  of  the  insect's 
ear-bag  does  not  appear  capable  of  responding  to  bodily  air- 
waves. This  adjective  is  important,  because  there  are  vi- 
bratory movements  of  matter  that  are  not  bodily  but 
molecular.  An  analogy  may  help  to  render  this  distinc- 
tion intelligible.  I  may  take  a  long  string  of  beads  and 
shake  it  into  wavelike  movements,  the  waves  being  formed 
by  the  movements  of  the  whole  string.  We  may  now  con- 
ceive another  kind  of  movement  or  vibration  by  supposing 
one  bead  to  receive  a  blow  pushing  it  forward,  this  push  to 
be  communicated  to  the  next,  then  to  the  third,  and  so 
on,  producing  a  minute  running  tremor  passing  from  end 
to  end.  This  kind  of  action  may  be  rendered  visible  by 
laying  a  number  of  billiard  balls  or  marbles  in  line  and 
bowling  an  outside  ball  against  the  end  one  of  the  row. 
The  impulse  will  be  rapidly  and  invisibly  transmitted  all 
along  the  line,  and  the  outer  ball  will  respond  by  starting 
forward. 

Heat,  light,  and  electricity  are  mysterious  internal  move- 
ments of  what  we  call  matter  (some  say  "ether,"  which  is 
but  a  name  for  imaginary  matter).  These  internal  move- 
ments are  as  invisible  as  those  of  the  intermediate  billiard 
balls  ;  but  if  there  be  a  line  of  molecules  acting  thus,  and 
the  terminal  one  strikes  an  organ  of  sense  fitted  to  receive 
its  motion,  some  sort  of  perception  may  follow.  When 
such  movements  of  certain  frequency  and  amplitude  strike 
our  organs  of  vision,  the  sensation  of  light  is  produced. 
When  others  of  greater  amplitude  and  smaller  frequency 


ANOTHER   WORLD  DOWN  HERE.  45 

strike  the  terminal  outspread  of  our  common  sensory 
nerves,  the  sensation  of  heat  results.  The  difference  be- 
tween the  frequency  and  amplitude  of  the  heat  waves  and 
the  light  waves  is  but  small,  or,  strictly  speaking,  there  is 
no  actual  line  of  separation  lying  between  them  ;  they  run 
directly  into  each  other.  When  a  piece  of  metal  is  gradu- 
ally heated,  it  is  first  "black-hot ; "  this  is  while  the  waves 
or  molecular  tremblings  are  of  a  certain  amplitude  and  fre- 
quency ;  as  the  frequency  increases  and  amplitude  dimin- 
ishes (or,  to  borrow  from  musical  terms,  as  the  pitch  rises), 
the  metal  becomes  dull  red-hot ;  greater  rapidity,  cherry 
red  ;  greater  still,  bright  red  ;  then  yellow-hot  and  white- 
hot  :  the  luminosity  growing  as  the  rapidity  of  molecular 
vibration  increases. 

There  is  no  such  gradation  between  the  most  rapid  undu- 
lations or  tremblings  that  produce  our  sensation  of  sound 
and  the  slowest  of  those  which  give  rise  to  our  sensations 
of  gentlest  warmth.  There  is  a  huge  gap  between  them, 
wide  enough  to  include  another  world  or  several  other 
worlds  of  motion,  all  lying  between  our  world  of  sounds 
and  our  world  of  heat  and  light,  and  there  is  no  good  rea- 
son whatever  for  supposing  that  matter  is  incapable  of  such 
intermediate  activity,  or  that  such  activity  may  not  give 
rise  to  intermediate  sensations,  provided  there  are  organs 
for  taking  up  and  sensifying  (if  I  may  coin  a  desirable 
word^  these  movements. 

As  already  stated,  the  limit  of  audible  tremors  is  three 
to  four  thousand  per  second,  but  the  smallest  number  of 
tremors  that  we  can  perceive  as  heat  is  between  three  and 
four  millions  of  millions  per  second.  The  number  of 
waves  producing  red  light  is  estimated  at  four  hundred 
and  seventy-four  millions  of  millions  per  second  ;  and  for 
the  production  of  violet  light,  six  hundred  and  ninety-nine 
millions  of  millions.  These  are  the  received  conclusions 
of  our  best  mathematicians,  which  I  repeat  on  their  au- 
thority. Allowing,  however,  a  very  large  margin  of  possi- 
ble error,  the  world  of  possible  sensations  lying  between 
those  produced  by  a  few  thousands  of  waves  and  any  num- 
ber of  millions  is  of  enormous  width. 

In  such  a  world  of  intermediate  activities  the  insect 


46  SCIENCE  IN  SHORT  CHAPTERS. 

probably  lives,  with  a  sense  of  vision  revealing  to  him  more 
than  our  microscopes  show  to  us,  and  with  his  minute  eye- 
like  ear-bag  sensifying  material  movements  that  lie  betAveen 
our  world  of  sounds  and  our  other  far-distant  worlds  of 
heat  and  light. 

There  is  yet  another  indication  of  some  sort  of  interme- 
diate sensation  possessed  by  insects.  Many  of  them  are 
not  only  endowed  with  the  thousands  of  lenses  of  their 
compound  eyes,  but  have  in  addition  several  curious  organs 
that  have  been  designated  "ocelli"  and  "stemmata." 
These  are  generally  placed  at  the  top  of  the  head,  the  thou- 
sand-fold eyes  being  at  the  sides.  They  are  very  much  like 
the  auditory  organs  above  described — so  much  so  that  in 
consulting  different  authorities  for  special  information  on 
the  subject  I  have  fallen  into  some  confusion,  from  which 
I  can  only  escape  by  supposing  that  the  organ  which  one 
anatomist  describes  as  the  ocelli  of  certain  insects  is  re- 
garded as  the  auditory  apparatus  when  examined  in  an- 
other insect  by  another  anatomist.  All  this  indicates  a 
sort  of  continuity  of  sensation  connecting  the  sounds  of 
the  insect  world  with  the  objects  of  their  vision. 

But  these  ocular  ears  or  auditory  eyes  of  the  insect  are 
not  his  only  advantage  over  us.  He  has  another  sensory 
organ  to  which,  with  all  our  boasted  intellect,  we  can  claim 
nothing  that  is  comparable,  unless  it  be  our  olfactory 
nerve.  The  possibility  of  this  I  will  presently  discuss. 

I  refer  to  the  antenna,  which  are  the  most  characteristic 
of  insect  organs,  and  wonderfully  developed  in  some,  as 
may  be  seen  by  examining  the  plumes  of  the  crested  gnat. 
Everybody  who  has  carefully  watched  the  doings  of  insects 
must  have  observed  the  curiously  investigative  movements 
of  the  antennas,  which  are  ever  on  the  alert,  peering  and 
prying  to  right  and  left  and  upwards  and  downwards. 
Huber,  who  devoted  his  life  to  the  study  of  bees  and  ants, 
concluded  that  these  insects  converse  with  each  other  by 
movements  of  the  antennas,  and  he  has  given  to  the  signs 
thus  produced  the  name  of  "antennal  language."  They 
certainly  do  communicate  information  or  give  orders  by 
some  means  ;  and  when  the  insects  stop  for  that  purpose, 
they  face  each  other  and  execute  peculiar  wavings  of  these 


ANOTHER    WORLD  DOWN  HERE.  47 

organs  that  are  highly  suggestive  of  the  movements  of  the 
old  semaphore  telegraph  arms. 

The  most  generally  received  opinion  is  that  these  an- 
tennas are  very  delicate  organs  of  touch,  but  some  recent 
experiments  made  by  Gustav  Hansen  indicate  that  they  are 
organs  of  smelling  or  of  some  similar  power  of  distinguish- 
ing objects  at  a  distance.  Flies  deprived  of  their  antenna 
ceased  to  display  any  interest  in  tainted  meat  that  had  pre- 
viously proved  very  attractive.  Other  insects  similarly 
treated  appear  to  become  indifferent  to  odors  generally. 
He  shows  that  the  development  of  the  antennae  in  different 
species  corresponds  to  the  power  of  smelling  which  they 
seem  to  possess. 

I  am  sorely  tempted  to  add  another  argument  to  those 
brought  forward  by  Hansen,  viz. :  that  our  own  olfactory 
nerves,  and  those  of  all  our  near  mammalian  relations,  are 
curiously  like  a  pair  of  antennas. 

There  are  two  elements  in  a  nervous  structure — the  gray 
and  the  white;  the  gray,  or  ganglionic  portion,  is  supposed 
to  be  the  centre  or  seat  of  nervous  power,  and  the  white 
medullary  or  fibrous  portion  merely  the  conductor  of  nerv- 
ous energy. 

The  nerves  of  the  other  senses  have  their  ganglia  seated 
internally,  and  bundles  of  tubular  white  threads  spread 
outwards  therefrom;  but  not  so  with  the  olfactory  nervous 
apparatus.  These  present  two  horn-like  projections  that 
are  thrust  forward  from  the  base  of  the  brain,  and  have 
white  or  medullary  stems  that  terminate  outwardly  or  an- 
teriorly in  ganglionic  bulbs  resting  upon  what  I  may  call  the 
roof  of  the  nose;  these  bulbs  throw  out  fibres  that  are  com- 
posed, rather  paradoxically,  of  more  gray  matter  than  white. 
In  some  quadrupeds  with  great  power  of  smell,  the  olfactory 
nerves  extend  so  far  forward  as  to  protrude  beyond  the  front 
of  the  hemispheres  of  the  brain,  with  bulbous  terminations 
relatively  very  much  larger  than  those  of  man. 

They  thus  appear  like  veritable  antennae.  In  some  of 
our  best  works  on  anatomy  of  the  brain  (Solly,  for  example) 
a  series  of  comparative  pictures  of  the  brains  Of  different 
animals  is  shown,  extending  from  man  to  the  cod-fish.  As 
we  proceed  downwards,  the  horn-like  projection  of  the  ol- 


48  SCIENCE  IN  SHORT  CHAPTERS. 

factory  nerves  beyoiid  the  central  hemispheres  goes  on  ex- 
tending more  and  more,  and  the  relative  magnitude  of 
the  terminal  ganglia  or  olfactory  lobes  increases  in  similar 
order. 

We  have  only  to  omit  the  nasal  bones  and  nostrils,  to 
continue  this  forward  extrusion  of  the  olfactory  nerves  and 
their  bulbs  and  branches,  to  coat  them  with  suitable  sheaths 
provided  with  muscles  for  mobility,  and  we  have  the  anten- 
nae of  insects.  I  submit  this  view  of  the  comparative  ana- 
tomy of  these  organs  as  my  own  speculation,  to  be  taken 
for  what  it  is  worth. 

There  is  no  doubt  that  the  antennae  of  these  creatures 
are  connected  by  nerve-stalks  with  the  anterior  part  of 
their  supra-oosophageal  ganglia,  i.e.,  the  nervous  centres 
corresponding  to  our  brain. 

But  what  kind  and  degree  of  power  must  such  olfactory 
organs  possess?  The  dog  has,  relatively  to  the  rest  of  his 
brain,  a  much  greater  development  of  the  olfactory  nerves 
and  ganglia  than  man  has.  His  powers  of  smell  are  so 
much  greater  than  ours  that  we  find  it  difficult  to  con- 
ceive the  possibility  of  what  we  actually  see  him  do.  As 
an  example,  I  may  describe  an  experiment  I  made  upon  a 
bloodhound  of  the  famous  Cuban  breed.  He  belonged  to 
a  friend  whose  house  is  situated  on  an  eminence  command- 
ing an  extensive  view.  I  started  from  the  garden  and  wan- 
dered about  a  mile  away,  crossed  several  fields  by  sinuous 
courses,  climbing  over  stiles,  and  jumping  ditches,  always 
keeping  the  house  in  view;  I  then  returned  by  quite  a  dif- 
ferent track.  The  bloodhound  was  set  upon  the  begin- 
ning of  my  track.  I  watched  him  from  a  window  gallop- 
ing rapidly,  and  following  all  its  windings  without  the  least 
halting  or  hesitation.  It  was  as  clear  to  his  nose  as  a 
gravelled  path  or  a  luminous  streak  would  be  to  our  eyes. 
On  his  return  I  went  down  to  him,  and  without  approach- 
ing nearer  than  five  or  six  yards,  he  recognized  me  as  the 
object  of  his  search,  proving  this  by  circling  round  me, 
baying  deeply  and  savagely  though  harmlessly,  as  he  always 
kept  at  about  the  same  distance.* 

*  What  did  he  smell?  Was  it  an  emanation  from  the  soles  of  my 
feet?  If  so,  how  did  this  aura  get  through  the  soles  of  my  boots, 


ANOTHER   WORLD  DOWN  HERB.  49 

If  the  difference  of  development  between  the  human  and 
canine  internal  antennas  produces  all  this  difference  of  func- 
tion, what  a  gulf  may  there  be  between  our  powers  of  per- 
ceiving material  emanations  and  those  possessed  by  insects! 
If  my  anatomical  hypothesis  is  correct,  some  insects  have 
protruding  nasal  organs  or  out-thrust  olfactory  nerves  as 
long  as  all  the  rest  of  their  bodies.  The  power  of  move- 
ment of  these  in  all  directions  affords  the  means  of  sensory 
communication  over  a  corresponding  range,  instead  of  being 
limited  merely  to  the  direction  of  the  nostril  openings.  In 
some  insects,  such  as  the  plumed  gnat,  the  antennae  do  not 
appear  to  be  thus  moveable,  but  this  want  of  mobility  is 
more  than  compensated  by  the  multitude  of  branchings  of 
these  wonderful  organs,  whereby  they  are  simultaneously 
exposed  in  every  direction.  This  structure  is  analogous  to 
the  fixed  but  multiplied  eyes  of  insects,  which,  by  seeing 
all  round  at  once,  compensate  for  the  want  of  that  mobility 
possessed  by  others  that  have  but  a  single  eyeball  mounted 
on  a  flexible  and  mobile  stalk;  that  of  the  spider,  for 
example. 

Such  an  extension  of  such  a  sensory  function  is  equiva- 
lent to  living  in  another  world  of  which  we  have  no  knowl- 
edge and  can  form  no  definite  conception.  We,  by  our 
senses  of  touch  and  vision,  know  the  shapes  and  colors  of 
objects,  and  by  our  very  rudimentary  olfactory  organs  form 
crude  ideas  of  their  chemistry  or  composition,  through  the 
medium  of  their  material  emanations;  but  the  huge  exag- 
geration of  this  power  in  the  insect  should  supply  him 
with  instinctive  perceptive  powers  of  chemical  analysis,  a 
direct  acquaintance  with  the  inner  molecular  constitution 
of  matter  far  clearer  and  deeper  than  we  are  able  to  obtain 
by  all  the  refinements  of  laboratory  analyses  or  the  hypo- 
thetical formulating  of  molecular  mathematicians.  Add 

which  were  thick?  It  could  scarcely  have  been  the  odor  of  the 
boot  soles  themselves  that  he  followed,  as  he  recognized  me  after- 
wards at  some  distance.  This  suggests  an  interesting  experiment, 
that  anybody  owning  one  of  these  dogs  may  easily  try.  Make  a 
similar  track  to  mine,  but  when  on  the  way,  take  off  the  boots  you 
wore  on  starting  and  change  them  for  some  one  else's  boots,  or  a 
new  pair,  and  watch  the  result  from  the  window. 


50  SCIENCE  IN  SHORT  CHAPTERS. 

this  to  the  other  world  of  sensations  producible  by  the 
vibratory  movements  of  matter  lying  between  those  per- 
ceptible by  our  organs  of  hearing  and  vision,  then  strain 
your  imagination  to  its  cracking  point,  and  you  will  still 
fail  to  picture  the  wonderland  in  which  the  smallest  of  our 
fellow-creatures  may  be  living,  moving,  and  having  their 
being. 


THE  OKIGIN  OF  LUNAR  VOLCANOES. 

MANY  theoretical  efforts,  some  of  considerable  violence, 
have  been  made  to  reconcile  the  supposed  physical  contra- 
diction presented  by  the  great  magnitude  and  area  of  former 
volcanic  activity  of  the  Moon,  and  the  present  absence  of 
water  on  its  surface.  So  long  as  we  accept  the  generally 
received  belief  that  water  is  a  necessary  agent  in  the  evolu- 
tion of  volcanic  forces,  the  difficulties  presented  by  the  lunar 
surface  are  rather  increased  than  diminished  by  further 
examination  and  speculation. 

We  know  that  the  lava,  scoriae,  dust  and  other  products 
of  volcanic  action  on  this  earth  are  mainly  composed  of 
mixed  silicates — those  of  alumina  and  lime  preponderating. 
When  we  consider  that  the  solid  crust  of  the  Earth  is  chiefly 
composed  of  silicic  acid,  and  of  basic  oxides  and  carbonates 
which  combine  with  silicic  acid  when  heated,  a  natural  ne- 
cessity for  such  a  composition  of  volcanic  products  becomes 
evident. 

If  the  Moon  is  composed  of  similar  materials  to  those 
of  the  Earth,  the  fusion  of  its  crust  must  produce  similar 
compounds,  as  they  are  formed  independently  of  any  atmos- 
pheric or  aqueous  agency. 

This  being  the  case,  the  phenomena  presented  by  the 
cooling  of  fused  masses  of  mixed  silicates  in  the  absence  of 
water  become  very  interesting.  Opportunities  of  studying 
such  phenomena  are  offered  at  our  great  iron-works,  where 
fused  masses  of  iron  cinder,  composed  mainly  of  mixed 
silicates,  are  continually  to  be  seen  in  the  process  of  cooling 
under  a  variety  of  circumstances, 


THE  ORIGIN  OF  LUNAR   VOLCANOES.  51 

I  have  watched  the  cooling  of  such  masses  very  fre- 
quently, and  have  seen  abundant  displays  of  miniature 
volcanic  phenomena,  especially  marked  where  the  cooling 
has  occurred  under  conditions  most  nearly  resembling  those 
of  a  gradually  cooling  planet  or  satellite;  that  is,  when  the 
fused  cinder  has  been  enclosed  by  a  solid  resisting  and  con- 
tracting crust. 

The  most  remarkable  that  I  have  seen  are  those  pre- 
sented by  the  cooling  of  the  "tap  cinder"  from  puddling 
furnaces.  This,  as  it  flows  from  the  furnace,  is  received  in 
stout  iron  boxes  ("cinder-bogies")  of  circular  or  rectangular 
horizontal  section.  The  following  phenomena  are  usually 
observable  on  the  cooling  of  the  fused  cinder  in  a  circular 
bogie. 

First  a  thin  solid  crust  forms  on  the  red-hot  surface. 
This  speedily  cools  sufficiently  to  blacken.  If  pierced  by  a 
slight  thrust  from  an  iron  rod,  the  red-hot  matter  within  is 
seen  to  be  in  a  state  of  seething  activity,  and  a  considerable 
quantity  exudes  from  the  opening.  If  a  bogie  filled  with 
fused  cinder  is  left  undisturbed,  a  veritable  spontaneous 
volcanic  eruption  takes  place  through  some  portion,  gener- 
ally near  the  centre,  of  the  solid  crust.  In  some  cases, 
this  eruption  is  sufficiently  violent  to  eject  small  spurts 
of  molten  cinder  to  a  height  equal  to  four  or  five  diame- 
ters of  the  whole  mass. 

The  crust  once  broken,  a  regular  crater  is  rapidly  formed, 
and  miniature  streams  of  lava  continue  to  pour  from  it; 
sometimes  slowly  and  regularly,  occasionally  with  jerks 
and  spurts  due  to  the  bursting  of  bubbles  of  gas.  The  ac- 
cumulation of  these  lava-streams  forms  a  regular  cone,  the 
height  of  which  goes  on  increasing.  I  have  seen  a  bogie 
about  10  or  12  inches  in  diameter,  and  9  or  10  inches  deep, 
thus  surmounted  by  a  cone  above  5  inches  high,  with  a  base 
equal  to  the  whole  diameter  of  the  bogie.  These  cones  and 
craters  could  be  but  little  improved  by  a  modeler  desiring 
to  represent  a  typical  volcano  in  miniature. 

Similar  craters  and  cones  are  formed  on  the  surface  of 
cinder  which  is  not  confined  by  the  sides  of  the  bogie.  I 
have  seen  them  well  displayed  on  the  "running-out  beds"  of 
refinery  furnaces.  These,  when  filled,  form  a  small  lake 


52  SCIENCE  IN  SHORT  CHAPTERS. 

of  molten  iron  covered  with  a  layer  of  cinder.  This  cinder 
first  skins  over,  as  in  the  bogies,  then  small  crevasses  form 
in  this  crust,  and  through  these  the  fused  cinder  oozes  from 
below.  The  outflow  from  this  chasm  soon  becomes  local- 
ized, so  as  to  form  a  single  crater,  or  a  small  chain  of 
craters;  these  gradually  develop  into  cones  by  the  accumla- 
tion  of  outflowing  lava,  so  that  when  the  whole  mass  has 
solidified,  it  is  covered  more  or  less  thickly  with  a  number 
of  such  hiUocks,  These,  however,  are  much  smaller  than  in 
the  former  case,  reaching  to  only  one  or  two  inches  in  height, 
with  a  proportionate  base.  It  is  evident  that  the  dimensions 
of  these  miniature  volcanoes  are  determined  mainly  by  the 
depth  of  the  molten  matter  from  which  they  are  formed. 
In  the  case  of  the  bogies,  they  are  exaggerated  by  the  over- 
powering resistance  of  the  solid  iron  bottom  and  sides, 
which  force  all  the  exudation  in  the  one  direction  of  least 
resistance,  viz.,  towards  the  centre  of  the  thin  upper  crust, 
and  thus  a  single  crater  and  a  single  cone  of  the  large  rela- 
tive dimensions  above  described  are  commonly  formed. 

The  magnitude  and  perfection  of  these  miniature  volca- 
noes vary  considerably  with  the  quality  of  the  pig-iron  and 
the  treatment  it  has  received,  and  the  difference  appears  to 
depend  upon  the  evolution  of  gases,  such  as  carbonic  oxide, 
volatile  chlorides,  fluorides,  etc.  I  mention  the  fluorides 
particularly,  having  been  recently  engaged  in  making  some 
experiments  on  Mr.  Henderson's  process  for  refining  pig- 
iron,  by  exposing  it  when  fused  to  the  action  of  a  mixture 
of  fluoride  of  calcium  and  oxides  of  iron,  alumina,  manga- 
nese, etc.  The  cinder  separated  from  this  iron  displayed  the 
phenomena  above  described  very  remarkably,  and  jets  of 
yellowish  flame  were  thrown  up  from  the  craters  while  the 
lava  was  flowing.  The  flame  was  succeeded  by  dense  white 
vapors  as  the  temperature  of  the  cinder  lowered,  and  a 
deposit  of  snow-like,  flocculent  crystals  was  left  upon  and 
around  the  mouth  or  crater  of  each  cone.  The  miniature 
representation  of  cosmical  eruptions  was  thus  rendered  still 
more  striking,  even  to  the  whito  deposit  of  the  haloid  salts 
which  Palmieri  has  described  as  remaining  after  the  recent 
eruption  of  Vesuvius. 

The  gases  thus  evolved  have  not  yet  been  analytically 


THE  ORIGIN  OF  LUNAR    VOLCANOES.  53 

examined,  and  the  details  of  the  powerful  reactions  dis- 
played in  this  process  still  demand  further  study;  but  there 
can  be  no  doubt  that  the  combination  of  silicic  acid  with 
the  base  of  the  fluor  spar  is  the  fundamental  reaction  to 
which  the  evolution  of  the  volatile  fluorides,  etc.,  is  mainly 
due. 

A  corresponding  evolution  of  gases  takes  place  in  cosmi- 
cal  volcanic  action,  whenever  silicic  acid  is  fused  in  con- 
tact with  limestone  or  other  carbonate,  and  a  still  closer 
analogy  is  presented  by  the  fusion»of  silicates  in  contact 
with  chlorides  and  oxides,  in  the  absence  of  water.  If  the 
composition  of  the  Moon  is  similar  to  that  of  the  Earth, 
chlorides  of  sodium,  etc.,  must  form  an  important  part  of 
its  solid  crust;  they  should  correspond  in  quantity  to  the 
great  deposit  of  such  salts  that  would  be  left  behind  if  the 
ocean  of  the  Earth  were  evaporated  to  dryness.  The  only 
assumptions  demanded  in  applying  these  facts  to  the  ex- 
planation of  the  surface  configuration  of  the  Moon  are,  1st, 
that  our  satellite  resembles  its  primary  in  chemical  compo- 
sition; 3d,  that  it  has  cooled  down  from  a  state  of  fusion; 
and  3d,  that  the  magnitude  of  the  eruptions,  due  to  such 
fusion  and  cooling,  must  bear  some  relation  to  the  quantity 
of  matter  in  action. 

The  first  and  second  are  so  commonly  made  and  under- 
stood, that  I  need  not  here  repeat  the  well-known  argu- 
ments upon  which  they  are  supported,  but  may  remark  that 
the  facts  above  described  afford  new  and  weighty  evidence 
in  their  favor. 

If  the  correspondence  between  the  form  of  a  freely  sus- 
pended and  rotating  drop  of  liquid  and  that  of  a  planet  or 
satellite  is  accepted  as  evidence  of  the  exertion  of  the  same 
forces  of  cohesion,  etc.,  on  both,  the  correspondence  be- 
tween the  configuration  of  the  lunar  surface,  and  that  of 
small  quantities  of  fused  and  freely  cooled  earth-crust  mat- 
ter, should  at  least  afford  material  support  to  the  other- 
wise indicated  inference,  that  the  materials  of  the  Moon's 
crust  are  similar  to  those  of  the  Earth's,  and  that  they  have 
been  cooled  from  a  state  of  fusion. 

I  think  I  may  safely  generalize  to  the  extent  of  saying, 
that  no  considerable  mass  of  fused  earthy  silicates  can  cool 


54  SCIENCE  IN  SHORT  CHAPTERS. 

down  under  circumstances  of  free  radiation  without  first 
forming  a  heated  solid  crust,  which,  by  further  radiation, 
cooling,  and  contraction,  will  assume  a  surface  configuration 
resembling  more  or  less  closely  that  of  the  Moon.  Evidence 
of  this  is  afforded  by  a  survey  of  the  spoil-banks  of  blast 
furnaces,  where  thousands  of  blocks  of  cinder  are  heaped 
together,  all  of  which  will  be  found  to  have  their  upper  sur- 
faces (that  were  freely  exposed  when  cooling)  corrugated 
with  radiating  miniature  lava  streams,  that  have  flowed 
from  one  or  more  craters  or  openings  that  have  been 
formed  in  the  manner  above  described. 

The  third  assumption  will,  I  think,  be  at  once  admitted, 
inasmuch  as  it  is  but  the  expression  of  a  physical  necessity. 

According  to  this,  the  Earth,  if  it  has  cooled  as  the 
Moon  is  supposed  to  have  done,  should  have  displayed  cor- 
responding irregularities,  and  generally,  the  magnitude  of 
mountains  of  solidified  planets  and  satellites  should  be  on 
a  scale  proportionate  to  their  whole  mass.  In  comparing 
the  mountains  of  the  Moon  and  Mercury  with  those  of  the 
Earth,  a  large  error  is  commonly  made  by  taking  the  cus- 
tomary measurements  of  terrestrial  mountain-heights  from 
the  sea-level.  As  those  portions  of  the  Earth  which  rise 
above  the  waters  are  but  its  upper  mountain  slopes,  and  the 
ocean  bottom  forms  its  lower  plains  and  valleys,  we  must 
add  the  greatest  ocean  depths  to  our  customary  measure- 
ments, in  order  to  state  the  full  height  of  what  remains  of 
the  original  mountains  of  the  Earth.  As  all  the  stratified 
rocks  have  been  formed  by  the  wearing  down  of  the  original 
upper  slopes  and  summits,  we  cannot  expect  to  be  able  to 
recognize  the  original  skeleton  form  of  our  water- washed 
globe. 

If  my  calculation  of  the  atmosphere  of  Mercury  is  cor- 
rect, viz.,  that  its  pressure  is  equal  to  about  one  seventh  of 
the  Earth's,  or  4^  inches  of  mercury,  there  can  be  no  liquid 
water  on  that  planet,  excepting  perhaps  over  a  small  amount 
of  circumpolar  area,  and  during  the  extremes  of  its  aphelion 
winter.  Thus  the  irregularities  of  the  terminator,  indicat- 
ing mountain  elevations  calculated  to  reach  to  -^^  of  the 
diameter  of  the  planet,  are  quite  in  accordance  with  the 
above-stated  theoretical  consideration. 


THE  ORIGIN  OF  LUNAR   VOLCANOES.  55 

There  is  one  peculiar  feature  presented  by  the  cones  of 
the  cooling  cinder  which  is  especially  interesting.  The 
flow  of  fused  cinder  from  the  little  crater  is  at  first  copious 
and  continuous;  then  it  diminishes  and  becomes  alternat- 
ing, by  a  rising  and  falling  of  the  fused  mass  within  the 
cone.  Ultimately  the  flow  ceases,  and  then  the  inner 
liquid  sinks,  more  or  less,  below  the  level  of  the  orifice.  In 
some  cases,  where  much  gas  is  evolved,  this  sinking  is  so 
considerable  as  to  leave  the  cone  as  a  mere  hollow  shell; 
the  inner  liquid  having  settled  down  and  solidified  with  a 
flat  or  slightly  rounded  surface,  at  about  the  level  of  the 
base  of  the  cone,  or  even  lower.  These  hollow  cones  were 
remarkably  displayed  in  some  of  the  cinder  of  the  Hender- 
son iron,  and  their  formation  was  obviously  promoted  by 
the  abundant  evolution  of  gas. 

If  such  hollow  cones  were  formed  by  the  cooling  of  a 
mass  like  that  of  the  Moon,  they  would  ultimately  and 
gradually  subside  by  their  own  weight.  But  how  would 
they  yield?  Obviously  by  a  gradual  hinge-like  bending  at 
the  base  towards  the  axis  of  the  cone.  This  would  occur 
with  or  without  fracture,  according  to  the  degree  of  visco- 
sity  of  the  crust,  and  the  amount  of  inclination.  But  the 
sides  of  the  hollow-cone  shell,  in  falling  towards  the  axis, 
would  be  crushing  into  smaller  circumferences.  What 
would  result  from  this?  I  think  it  must  be  the  formation 
of  fissures,  extending,  for  the  most  part,  radially  from  the 
crater  towards  the  base,  and  a  crumpling  up  of  the  shell  of 
the  cone  by  foldings  in  the  same  direction.  Am  I  ventur- 
ing too  far  in  suggesting  that  in  this  manner  may  have 
been  formed  the  mysterious  rays  and  rills  that  extend  so 
•Abundantly  from  several  of  the  lunar  craters? 

The  upturned  edges  or  walls  of  the  broken  crust,  and 
the  chasms  necessarily  gaping  between  them, 'appear  to 
satisfy  the  peculiar  phenomena  of  reflection  which  these 
rays  present.  These  edges  of  the  fractured  crust  would 
lean  towards  each  other,  and  form  angular  chasms;  while 
the  foldings  of  the  crust  itself  would  form  long  concave 
troughs,  extending  radially  from  the  crater. 

These,  when  illuminated  by  rays  falling  upon  them  in 
the  direction  of  the  line  of  vision]!  must  reflect  more  light 


56  SCIENCE  IN  SHORT  CHAPTERS. 

towards  the  spectator  than  does  the  general  convex  lunar 
surface,  and  thus  they  become  especially  visible  at  the  full 
Moon. 

Such  foldings  and  fractures  would  occur  after  the  subsi- 
dence and  solidification  of  the  lava-forming  liquid — that  is, 
when  the  formation  of  new  craters  had  ceased  in  any  given 
region;  hence  they  would  extend  across  the  minor  lateral 
craters  formed  by  outbursts  from  the  sides  of  the  main 
cone,  in  the  manner  actually  observed. 

The  fact  that  the  bottoms  of  the  great  walled  craters  of 
the  Moon  are  generally  lower  than  the  surrounding  plains 
must  not  be  forgotten  in  connection  with  this  explanation. 

I  will  not  venture  farther  with  the  speculations  suggested 
by  the  above-described  resemblances,  as  my  knowledge  of 
the  details  of  the  telescopic  appearances  of  the  Moon  is  but 
second-hand.  I  have  little  doubt,  however,  that  observers 
who  have  the  privilege  of  direct  familiarity  with  such  de- 
tails, will  find  that  the  phenomena  presented  by  the  cooling 
of  iron  cinder,  or  other  fused  silicates,  are  worthy  of 
further  and  more  careful  study. 


NOTE  ON  THE  DIEEOT  EFFECT  OF  SUN-SPOTS 
ON  TERRESTRIAL  CLIMATES. 

PKOFESSOR  LABTGLEY  determines  quantitatively  the  ef- 
fects respectively  produced  by  the  radiations  from  the  solar 
spots,  penumbra,  and  photosphere  upon  the  face  of  a  ther- 
mopile, and  infers  that  these  effects  measure  their  relative 
influence  on  terrestrial  climate. 

In  thus  assuming  that  the  heat  communicated  to  the 
thermopile  measures  the  solar  contribution  to  terrestrial 
climate,  Professor  Langley  omits  an  important  factor,  viz., 
the  amount  of  heat  absorbed  in  traversing  the  earth's 
atmosphere;  and  in  measuring  the  relative  efficiency  of  the 
spots,  penumbra,  and  photosphere,  he  has  not  taken  into 
account  the  variations  of  diathermancy  of  the  intervening 


SUN-SPOTS  ON  TERRESTRIAL   CLIMATES.          57 

atmospheric  matter,  which  are  due  to  the  variations  in  the 
source  of  heat. 

Speaking  generally,  it  maybe  affirmed  that  the  radiations 
of  obscure  heat  are  more  largely  absorbed  by  the  gases  and 
vapors  of  our  atmosphere  than  those  of  luminous  heat, 
and  the  great  differences  in  the  mere  luminosity  of  the 
spots,  penumbra,  and  photosphere  justify  the  assumption 
that  the  radiations  of  a  sun-spot  will  (to  use  the  expressive 
simile  of  Tyndall)  lose  far  more  by  atmospheric  sifting  than 
will  those  from  the  photosphere. 

But  the  spot  areas  will  be  none  the  less  effective  on 
terrestrial  climate  on  that  account.  A  given  amount  of 
heat  arrested  by  the  earth's  atmosphere  will  have  even 
greater  climatic  efficiency  than  if  received  upon  its  solid 
surface,  inasmuch  as  the  gases  are  worse  radiators  than  the 
rocks,  and  will  therefore,  cceteris  paribus,  retain  a  larger 
proportion  of  the  heat  they  receive. 

I  have  long  ago  endeavored  to  show*  that  the  depth  of 
the  photosphere,  from  the  solar  surface  inwards,  is  limited 
by  dissociation  ;  that  the  materials  of  the  Sun  within  the 
photosphere  exist  in  a  dissociated,  elementary  condition ; 
that  at  the  photosphere  they  are,  for  the  most  part,  com- 
bined. This  view  has  since  been  adopted  by  many  eminent 
solar  physicists,  and  if  correct,  demands  a  much  higher 
temperature  within  the  depths  revealed  by  that  withdrawal 
of  the  photospheric  vail  which  constitutes  a  sun-spot. 

If  I  am  right  in  this,  and  also  in  supposing  the  spot- 
radiations  to  be  so  much  more  abundantly  absorbed  than 
those  of  the  photosphere,  and  if  in  spite  of  this  higher  tem- 
perature of  the  spots,  the  surface  of  the  earth  receives  from 
them  the  lower  degree  of  heat  measured .  by  Professor 
Langley,  another  interesting  consequence  must  follow.  The 
excess  of  spot-heat  directly  absorbed  by  the  atmosphere, 
and  mainly  by  the  water  dissolved  or  suspended  in  its  upper 
regions,  must  be  especially  effective  in  dissipating  clouds 
and  checking  or  modifying  their  formation.  The  meteoro- 
logical results  of  this  may  be  important,  and  are  worthy  of 
careful  study. 

*  "  The  Fuel  of  the  $un,"  Chapters  iv.  to  r. 


58  SCIENCE  IN  SHORT  CHAPTERS. 

In  thus  venturing  to  question  some  of  Professor 
Langley's  inferences  I  am  far  from  underrating  the  interest 
and  importance  of  his  researches.  On  the  contrary,  I  re- 
gard the  quantitative  results  he  has  obtained  as  especially 
valuable  and  opportune,  in  affording  means  of  testing  the 
above-named  and  other  speculations  in  solar  physics. 
Similar  observations  repeated  at  different  elevations  would 
decide,  so  far  as  the  lower  regions  are  concerned,  whether 
or  not  there  is  any  difference  in  the  quantity  of  heat  im- 
parted by  the  bright  and  obscure  portions  of  the  Sun  to 
our  atmosphere.  If  the  differences  already  observed  by 
Professor  Langley  vary  in  ascending,  a  new  means  will  be 
afforded  of  studying  the  constitution  of  the  interior  of  the 
Sun  and  its  relations  to  the  photosphere.  Direct  evidence 
of  selective  absorption  by  our  atmosphere  may  thus  be  ob- 
tained, which  would  go  far  towards  solving  one  of  the  cru- 
cial solar  problems,  viz.,  whether  the  darker  regions  are 
hotter  or  cooler' than  the  photosphere. 

The  obscure  radiations  from  the  moon  must  be  absorbed 
by  our  atmosphere  like  those  from  the  sun-spot,  and  may  be 
sufficiently  effective  to  account  for  the  alleged  dissipation  of 
clouds  by  the  full  moon. 

In  both  cases  the  climatic  influence  is  greatly  heightened 
by  the  fact  that  all  the  heat  thus  absorbed  is  directly 
effective  in  raising  the  temperature  of  the  air.  The  action 
of  the  absorbed  heat  in  reference  to  cloud-formation  is 
directly  opposite  to  that  of  the  transmitted  solar  heat,  as 
this  reaching  the  surface  of  the  earth  evaporates  the  super- 
ficial water,  and  thereby  produces  the  material  of  clouds. 
On  the  other  hand,  the  heat  which  is  absorbed  by  the  air 
increases  its  vapor-holding  capacity,  and  thus  prevents  the 
formation  of  clouds,  or  even  effects  the  dissolution  of 
clouds  already  formed. 


THE  PHILOSOPHY  OF  THE  RADIOMETER. 


THE  PHILOSOPHY  OF  THE  RADIOMETER  AND 
ITS  COSMICAL  REVELATIONS. 

So  much  speculation,  and  not  a  little  extravagant  specu- 
lation, has  been  devoted  to  the  dynamics  of  the  radiometer, 
that  I  feel  some  compunction  in  adding  another  stone  to 
the  heap,  my  only  apology  and  justification  for  so  doing 
being  that  I  propose  to  regard  the  subject  from  a  very  un- 
sophisticated point  of  view,  and  with  somewhat  heretical 
directness  of  vision — i.e.,  quite  irrespective  of  atoms,  mole- 
cules, or  ether,  or  any  other  specific  preconceptions  con- 
cerning the  essential  kinetics  of  radiant  forces,  beyond  that 
of  regarding  such  forces  as  affections  or  conditions  of  mat- 
ter which  are  transmitted  radially  in  constant  quantity,  and 
therefore  obey  the  necessary  law  of  radial  diffusion  or  in- 
verse squares. 

The  primary  difficulty  which  appears  to  have  generally 
been  suggested  by  the  movements  of  the  radiometer,  is  the 
case  which  it  seems  to  present  of  mechanical  action  with- 
out any  visible  basis  of  corresponding  reaction  :  a  visible 
tangible  object  pushed  forward,  without  any  visible  push- 
ing agent  or  resisting  fulcrum  against  which  the  moving 
body  reacts. 

This  difficulty  has  been  met  by  the  invocation  of  obedi- 
ent and  vivacious  molecules  of  residual  atmospheric  matter, 
which  have  been  called  upon  to  bound  and  rebound  between 
the  vanes  and  the  inner  surfaces  of  the  glass  envelope  of 
the  instrument. 

How  is  it  that  the  advocates  of  these  activities  have  not 
sought  to  verify  their  speculations  by  modifying  the  shape 
and  dimensions  of  the  exhausted  glass  bulb  or  receiver  ?  * 
If  the  motion  of  the  radiometer  is  due  to  such  excursions 
and  collisions,  the  length  of  excursion  and  the  angles  of 
collision  must  modify  its  motions ;  and  such  modification 
under  given  conditions  would  form  a  fine  subject  for  the 
exercise  of  the  ingenuity  of  molecular  mathematicians.  If 

*  Since  this  was  written  some  such  modifications  have  been  made 
with  equivocal  results. 


60  SCIENCE  IN  SHORT  CHAPTERS. 

their  hypothetical  data  are  sound,  they  should  be  able  to 
predict  the  relative  velocities  or  torsion-force  of  a  series  of 
radiometers  of  similar  construction  in  all  other  respects, 
but  with  variable  shapes  and  diameters  of  enclosing 
vessels. 

If  we  divest  our  minds  of  all  visions  of  hypothetical 
atoms,  molecules,  ethers,  etc.,  and  simply  look  at  the  facts 
of  radiation  with  the  same  humility  of  intellect  as  we  usually 
regard  gravitation,  this  primary  difficulty  of  the  radiometer 
at  once  vanishes.  The  force  of  gravitation  is  a  radiant  force 
acting  somehow  between,  or  upon,  or  by  distant  bodies  ;  and 
these  bodies,  however  far  apart,  act  and  react  upon  each 
other  with  mutual  forces,  precisely  equal  and  exactly  con- 
trary. We  conceive  the  sun  pulling  the  earth  in  a  certain 
direction,  and  receiving  from  the  earth  an  equal  pull  in  a 
precisely  contrary  direction,  and  we  have  hitherto  demanded 
no  ethereal  or  molecular  link  for  the  transmission  of  these 
mutually  attractive  forces.  Why,  then,  should  we  not  re- 
gard radiant  repulsive  energy  in  the  same  simple  manner  ? 

If  we  do  this  there  is  no  difficulty  in  finding  the  ultimate 
reaction  fulcrum  of  the  radiometer  vanes.  It  is  simply  the 
radiating  body,  the  match,  the  candle,  the  lamp,  the  sun, 
or  whatever  else  may  be  the  source  of  the  impelling  radia- 
tions. According  to  this  view,  the  radiant  source  must  be 
repelled  with  precisely  the  same  energy  as  the  arms  or  pen- 
dulum of  the  radiometer ;  and  it  would  move  backward  or 
in  opposite  direction  if  equally  free  to  move.  If,  by  any 
means,  we  cause  the  glass  envelope  of  the  radiometer  to  be- 
come the  radiant  source,  it  should  be  repelled,  and  may 
even  rotate  in  opposite  direction  to  the  vanes,  or  vice  versa. 
This  has  been  done  with  floating  radiometers. 

Viewed  thus  as  simple  matter  of  fact,  irrespective  of  any 
preconceived  kinetics  of  intervening  media,  the  net  result 
of  Mr.  Crookes's  researches  become  nothing  less  than  the 
discovery  of  a  new  law  of  nature  of  great  magnitude  and 
the  broadest  possible  generality,  viz.,  that  the  sun  and  all 
other  radiant  bodies— i.e.,  all  the  materials  of  the  universe 
— exert  a  mechanical  repulsive  force,  in  addition  to  the 
calorific,  luminous,  actinic,  and  electrical  forces  with  which 
they  have  hitherto  been  credited.  He  has  shown  that  this 


THE  PHILOSOPHY  OF  THE  RADIOMETER.         61 

force  is  refrangible  and  dispersible,  that  it  is  outspread  with 
the  spectrum,  but  is  most  concentrated,  or  active,  in  the 
region  of  the  ultra-red  rays,  and  progressively  feeblest  in  the 
violet ;  or,  otherwise  stated,  it  exists  in  closer  companion- 
ship with  heat  than  with  light,  and  closer  with  light  than 
with  actinism. 

According  to  the  doctrine  of  exchanges,  which  has  now 
passed  from  the  domain  of  theory  to  that  of  demonstrated 
law,  all  bodies,  whatever  be  their  temperature,  are  per- 
petually radiating  heat-force,  the  amount  of  which  varies, 
cwteris  paribus,  with  their  temperature.  If  we  now  add 
to  this  generalization  that  all  bodies  are  similarly  radiating 
mechanical  force  and  suffering  corresponding  mechanical 
reaction,  the  theoretical  difficulties  of  the  radiometer  vanish. 
What  must  follow  in  the  case  of  a  freely  suspended  body 
unequally  heated  on  opposite  sides? 

It  must  be  repelled  in  a  direction  perpendicular  to  the 
surface  of  its  hottest  side.  If  two  rockets  were  affixed  to 
opposite  sides  of  a  pendant  body,  and  were  to  exert  unequal 
ejective  forces,  the  reaction  of  the  stronger  rocket  would 
repel  the  body  in  the  opposite  direction  to  its  preponderat- 
ing ejection.  This  represents  the  radiometer  vane  with  one 
side  blackened  and  the  other  side  bright.  When  exposed 
to  luminous  rays  the  black  side  becomes  warmer  than  the 
bright  side  by  its  active  absorption  and  conversion  of  light 
into  heat,  and  thus  the  blackened  face  radiates  in  excess  and 
recedes. 

We  may  regard  it  thus  as  acting  by  its  own  radiations, 
or  otherwise  as  acted  upon  by  the  more  powerful  radiant 
whose  rays  are  differentially  received  by  the  black  and 
bright  sides.  These  different  modes  of  regarding  the  action 
are  perfectly  consistent  with  each  other,  and  analogous  to 
the  two  different  modes  of  regarding  gravitation,  when  we 
describe  the  sun  as  attracting  the  earth,  or,  otherwise,  the 
earth  as  gravitating  to  the  sun.  Strictly  speaking,  neither 
of  these  descriptions  is  correct,  as  the  gravitation  is  mu- 
tual, and  the  total  quantity  exerted  between  the  sun  and 
the  earth  is  equal  to  the  sum  of  their  energies,  but  it  is 
sometimes  convenient  to  regard  the  action  from  a  solar 
standpoint,  and  at  others  from  a  terrestrial.  So  with  the 


62  SCIENCE  IN  SHORT  CHAPTERS. 

radiometer  and  the  strictly  mutual  repulsions  between  it 
and  the  predominating  radiant. 

It  appears  to  me  that  this  unsophisticated  conception  of 
radiant  mechanical  repulsive  force,  and  its  necessary  me- 
chanical reaction  on  the  radiant  body,  meets  all  the  facts 
at  present  revealed  'by  the  experiments  of  Mr.  Crookes  and 
others. 

The  attraction  which  occurs  when  the  disc  of  the  radio- 
meter is  surrounded  with  a  considerable  quantity  of  atmos- 
pheric matter  is  probably  due  to  inequality  of  atmospheric 
pressure.  The  absorbing  face  of  the  disc  becomes  heated 
above  the  temperature  of  the  opposite  face,  the  film  of-  air 
in  contact  with  the  warmer  face  rises,  leaving  a  relatively 
vacuous  space  in  front.  This  produces  a  rush  of  air  from 
back  to  front  which  carries  the  radiometer  vane  with  it. 
When  the  exhaustion  of  the  radiometer  is  carried  so  far  that 
the  residual  air  is  only  just  sufficiently  dense  to  neutralize 
the  direct  repulsion  of  radiation,  the  neutral  point  is 
reached.  When  exhaustion  is  carried  beyond  this,  repulsion 
predominates. 

Taking  Mr.  Crookes's  estimate  of  the  mechanical  energy 
of  solar  radiation  at  32  grains  per  square  foot,  2  cwts.  per 
acre,  57  tons  per  square  mile,  etc.,  and  accepting  these  as 
they  are  offered,  i.  <?.,  merely  as  provisional  and  approxi- 
mate estimates,  we  are  led  to  a  cosmical  inference  of  the 
highest  importance,  one  that  must  materially  modify  our 
interpretations  of  some  of  the  grandest  phenomena  of  the 
universe.  Although  the  estimated  sunlight  pressure  upon 
the  earth,  the  three  thousand  millions  of  tons,  is  too  small 
a  fraction  of  the  earth's  total  weight  to  effect  an  easily 
measurable  increase  of  the  length  of  our  year,  the  case  is 
quite  otherwise  with  the  asteroids  and  the  zones  of  meteoric 
matter  revolving  around  the  sun. 

The  mechanical  repulsion  of  radiation  is  a  superficial  ac- 
tion, and  must,  therefore,  vary  with  the  amount  of  surface 
exposed,  while  that  of  gravitation  varies  with  the  mass; 
Thus  the  ratio  of  radiant  repulsion  to  the  attraction  of 
gravitation  goes  on  increasing  with  the  subdivison  of  masses, 
and  becomes  an  important  fraction  in  the  case  of  the  smaller 
bodies  of  the  solar  system.  A  zone  of  meteorites  traveling 


THE  PHILOSOPHY  OF  THE  RADIOMETER.         63 

around  the  sun  would  be  broken  up,  sifted,  and  sorted  into 
different  orbits,  according  to  their  diameters,  if  this  super- 
ficial repulsion  operated  against  gravitation  without  any 
compensating  agency.  Gravitation  would  be  opposed  in 
various  degrees,  neutralized,  and,  in  the  case  of  cosmic  dust, 
even  reversed.  Comets  presenting  so  large  a  surface  in 
proportion  to  their  mass  would  either  be  driven  away  alto- 
gether or  forced  to  move  in  orbits  utterly  disobedient  to 
present  calculations.  This  would  occur  if  the  inter-planet- 
ary spaces  were  as  nearly  vacuous  as  the  torsion  instrument 
with  which  Mr.  Crookes  made  his  measurements. 

Kegarding  the  properties  of  our  atmosphere  only  in  the 
light  of  experimental  data,  irrespective  of  imaginary  mole- 
cules, and  their  supposed  gyrations  or  oscillations,  we  see 
at  once  that  an  inter-planetary  or  inter-stellar  vacuum  must 
act  like  a  Sprengel  pump  upon  our  atmosphere,  upon  the 
atmosphere  of  other  planets,  and  upon  those  of  the  sun 
and  the  stars,  and  would  continue  such  action  until  an 
equilibrium  between  the  repulsive  energy  of  the  gas  and  the 
gravitation  of  the  solid  orbs  had  been  established.  Atmos- 
pheric matter  would  thus  be  universally  diffused,  with 
special  accumlations  around  solid  orbs,  varying  in  quantity 
with  their  respective  gravitating  energy.  Such  a  universal 
atmosphere  would  accelerate  orbital  motion,  and  this  ac- 
celeration would  vary  with  the  surface  of  bodies.  Its  action 
being  thus  exactly  opposed  to  that  of  radiant  repulsion,  it 
must,  at  a  certain  density,  exactly  neutralize  it.  That  it 
does  this  is  evident  from  the  obedience  of  all  the  elements 
of  the  solar  system  to  the  calculated  action  of  gravitation; 
and  thus  Mr.  Crookes'qgjesearches  not  only  confirm  the  idea 
of  universal  atmospheric  diffusion,  but  they  afford  a  means 
by  which  we  may  ultimately  measure  the  actual  density  of 
the  universal  atmosphere.  If,  as  I  have  endeavored  to  show 
in  my  essay  on  "The  Fuel  of  the  Sun,"  the  initial  radiant 
energy  of  every  star  depends  upon  its  mass,  and  its  conse- 
quent condensation  of  atmospheric  matter,  the  density  of 
inter-planetary  atmosphere  sufficient  to  neutralize  the  radi- 
ant mechanical  energy  of  our  sun  may  be  the  same  as  is 
demanded  to  perform  the  same  function  for  all  the  stars  of 


64  SCIENCE  IN  SHORT  CHAPTERS. 

the  universe,  and  all  their  attendant  worlds,  comets,  and 
meteors. 

In  order  to  prevent  misunderstanding  of  the  above,  I 
must  add  that  I  have  therein  studiously  assumed  a  negative 
position  in  reference  to  all  hypothetical  conceptions  of  the 
nature  of  heat,  light,  etc.,  and  their  modes  of  transmission, 
simply  because  I  feel  satisfied  that  the  subject  has  hitherto 
been  obscured  and  complicated  by  overstrained  efforts  to  fit 
the  phenomena  to  the  excessively  definite  hypotheses  of 
modern  molecular  mathematicians.  The  atoms  invented  by 
Dalton  for  the  purpose  of  explaining  the  demonstrated  laws 
of  chemical  combination  performed  this  function  admirably, 
and  had  great  educational  value,  so  long  as  their  purely 
imaginary  origin  was  kept  in  view;  but  when  such  atoms  are 
treated  as  facts,  and  physical  dogmas  are  based  upon  the 
assumption  of  their  actual  existence,  they  become  dangerous 
physical  superstitions.  Regarding  matter  as  continuous, 
i.  e.,  supposing  it  to  be  simply  as  it  appears  to  be,  and  co- 
extensive with  the  universe,  in  accordance  with  the  experi- 
mental evidences  of  the  unlimited  expansibility  of  gaseous 
matter,  we  need  only  assume  that  our  sensations  of  heat, 
light,  etc.,  are  produced  by  active  conditions  of  such  mat- 
ter analogous  to  those  which  are  proved  to  produce  our  sen- 
sations of  sound.  On  this  basis  there  is  no  difficulty  in 
conceiving  the  rationale  of  the  reaction  which  produces  the 
repulsion  of  the  radiometer.  I  may  even  go  further,  and 
affirm  that  it  is  impossible  to  rationally  conceive  radiation 
producing  any  mechanical  effects  without  mechanical  reac- 
tion. If  heat  be  motion,,  and  actual  motion  of  actual 
matter,  mechanical  force  must  be  exerted  to  produce  it,  and 
a  body  which  is  warmer  on  one  side  than  the  other,  i.  e., 
which  is  exerting  more  outward  motion-producing  force  on 
one  side  than  on  the  other,  must  be  subject  to  proportionally 
unequal  reaction,  and,  therefore,  if  free  to  move,  must  re- 
treat in  a  direction  contrary  to  that  of  its  greater  activity. 
Regarded  thus,  the  residual  air  of  the  radiometer  does  act, 
not  by  collisions  of  particles  between  the  vane  and  inside  of 
the  glass  vessel,  but  by  the  direct  reaction  of  the  radiant 
energy  which  would  operate  irrespective  of  vessels,  i.  e., 
upon  naked  radiometer  vanes  if  carried  halfway  to  the 


ON  THE  SOCIAL  BENEFITS  OF  PARAFFIN.        65 

moon,,  or  otherwise  freed  from  excess  of  atmospheric  em- 
barrassment. 

The  recent  experiments  of  Mr.  Crookes,  showing  retarda- 
tion of  the  radiometer  with  extreme  exhaustion,  seem  to 
indicate  that  heat-rays,  like  the  electric  discharge,  demand 
a  certain  amount  of  atmospheric  matter  as  their  carrier. 

I  cannot  conclude  these  hasty  and  imperfect  notes,  writ- 
ten merely  with  suggestive  intent,  without  quoting  a  pas- 
sage from  the  preface  to  the  "  Correlation  of  Physical 
Forces,"  which,  though  written  so  long  ago,  appeal's  to  me 
worthy  of  the  profoundest  present  consideration. 

"  It  appears  to  me  that  heat  and  light  maybe  considered 
as  affections;  or,  according  to  the  undulatory  theory,  vibra- 
tions of  matter  itself,  and  not  of  a  distinct  ethereal  fluid 
permeating  it:  these  vibrations  would  be  propagated  just 
as  sound  is  propagated  by  vibrations  of  wood  or  as  waves 
by  water.  To  my  mind  all  the  consequences  of  the  undu- 
latory theory  flow  as  easily  from  this  as  from  the  hypothesis 
of  a  specific  ether;  to  suppose  which,  namely,  to  suppose 
a  fluid  sui  generis  and  of  extreme  tenuity  penetrating  solid 
bodies,  we  must  assume,  first,  the  existence  of  the  fluid  it- 
self; secondly,  that  bodies  are  without  exception  porous; 
thirdly,  that  these  pores  communicate;  fourthly,  that  mat- 
ter is  limited  in  expansibility.  None  of  these  difficulties 
apply  to  the  modification  of  this  theory  which  I  venture  to 
propose:  and  no  other  difficulty  applies  to  it  which  does 
not  equally  apply  to  the  received  hypothesis." 


ON  THE  SOCIAL  BENEFITS  OF  PARAFFIN. 

To  the  inhabitants  of  Jupiter,  who  have  always  one, 
two,  or  three  of  their  four  moons  in  active  and  efficient 
radiation,  or  of  Saturn  displaying  the  broad  luminous 
oceans  of  his  mighty  rings  in  addition  to  the  minor  lamps 
of  his  eight  ever- changeful  satellites,  the  relative  merits  of 
rushlights,  candles,  lamps,  and  gaslights  may  be  a  question 
of  indifference;  but  to  us,  the  residents  of  a  planet  which 


66  SCIENCE  IN  SHORT  CHAPTERS. 

has  but  one  small  moon  that  only  displays  her  nearly  full 
face  during  a  few  nights  of  each  month,  the  subject  of 
artificial  light  is  only  second  in  importance  to  those  of 
food  and  artificial  heat,  and  every  step  that  is  made  in  the 
improvement  of  our  supplies  of  this  primary  necessary 
must  have  a  momentous  influence  on  the  physical  comfort, 
and  also  upon  the  intellectual  and  moral  progress,  of  this 
world's  human  inhabitants. 

If  a  cockney  Eip  Van  Winkle  were  to  revisit  his  old 
haunts,  the  changes  produced  by  the  introduction  of  gas 
would  probably  surprise  him  the  most  of  all  he  would  see. 
He  would  be  astonished  to  find  respectable  people,  and 
even  unprotected  females,  going  alone,  unarmed  and  with- 
out fear,  at  night,  up  the  by-streets  which  in  his  days  were 
deemed  so  dangerous,  and  he  would  soon  perceive  that  the 
bright  gaslights  had  done  more  than  all  the  laws,  the  ma- 
gistrates, and  the  police,  to  drive  out  those  crimes  which 
can  only  flourish  in  darkness.  The  intimate  connection 
between  physical  light  and  moral  and  intellectual  light 
and  progress  is  a  subject  well  worthy  of  an  exhaustive 
treatise. 

We  must,  however,  drop  the  general  subject  and  come 
down  to  our  particular  paraffin  lamp.  In  the  first  place, 
this  is  the  cheapest  light  that  has  ever  been  invented — 
cheaper  than  any  kind  of  oil  lamp — cheaper  than  the 
cheapest  and  nastiest  of  candles,  and,  for  domestic  pur- 
poses, cheaper  than  gas.  For  large  warehouses,  shops, 
streets,  public  buildings,  etc.,  it  is  not  so  cheap  as  gas 
should  be,  but  is  considerably  cheaper  than  gas  actually  is 
at  the  price  extorted  by  the  despotism  of  commercial 
monopoly. 

The  reason  why  it  is  especially  cheaper  for  domestic  pur- 
poses is,  first,  because  the  small  consumer  of  gas  pays  a 
higher  price  than  the  large  consumer;  and  secondly,  be- 
cause a  lamp  can  be  placed  on  a  table  or  wherever  else  its 
light  is  required,  and  therefore  a  small  lamp  flame  will  do 
the  work  of  a  much  larger  gas  flame.  We  must  remember 
that  the  intensity  of  light  varies  inversely  with  the  square 
of  the  distance  from  the  source  of  light;  thus  the  amount 
of  light  received  by  this  page  from  a  light  at  one  foot  dis- 


ON  THE  SOCIAL  BENEFITS  OF  PARAFFIN.        67 

tance  is  four  times  as  great  as  if  it  were  two  feet  distant, 
nine  times  as  great  as  at  three  feet,  sixteen  times  as  great 
as  at  four  feet,  one  hundred  times  as  great  as  at  ten  feet, 
and  so  on.  Hence  the  necessity  of  two  or  three  great  flames 
in  a  gas  chandelier  suspended  from  the  ceiling  of  a  moderate- 
sized  room. 

In  a  sitting-room  lighted  thus  with  gas,  we  are  obliged, 
in  order  to  read  comfortably  by  the  distant  source  of  light, 
to  burn  so  much  gas  that  the  atmosphere  of  the  room  is 
seriously  polluted  by  the  products  of  this  extravagant  com- 
bustion. A  lamp  at  a  moderate  distance — say  eighteen 
inches  or  two  feet,  or  thereabouts— will  enable  us  to  read 
or  work  with  one-tenth  to  one-twentieth  the  amount  of 
combustion,  and  therefore  Avith  so  much  less  vitiation  of 
the  atmosphere,  and,  if  we  use  a  paraffin  lamp,  at  much 
less  expense. 

But  the  chief  value  of  the  paraffin  lamp  is  felt  where  gas 
is  not  obtainable — in  the  country  mansion  or  villa,  the 
farmhouse,  and,  most  of  all,  in  the  poor  man's  cottage. 
We  have  Bible  Societies  for  providing  cheap  Bibles;  we 
have  cheap  standard  works,  cheap  magazines,  cheap  news- 
papers, etc.;  but  all  these  are  unavailable  to  the  poor  man 
until  he  can  get  a  good  and  cheap  light  wherewith  to  read 
them  at  the.  only  time  he  has  for  reading,  viz.,  in  the  even- 
ings, when  his  work  is  done.  One  shilling's  worth  of  cheap 
literature  will  require  two  shillings'  worth  of  dear  candles 
to  supply  the  light  necessary  for  reading  it.  Therefore,  the 
cheapening  of  light  has  quite  as  much  to  do  with  the  poor 
man's  intellectual  progress  as  the  cheapening  of  books  and 
periodicals. 

For  a  man  to  read  comfortably,  and  his  wife  to  do  her 
needlework,  they  must  have  a  candle  for  each,  if  dependent 
on  tallow  dips.  They  may,  and  do,  struggle  on  with  one 
such  candle,  but  the  inconvenience  soon  sickens  them  of 
their  occupation  ;  the  man  lolls  out  for  an  idle  stroll,  soon 
encounters  a  far  more  bright  and  cheerful  room  than  the 
gloomy  one  he  has  just  left,  and,  moth-like,  he  is  attracted 
by  the  light,  and  finishes  up  his  evening  in  the  public- 
house. 

We  may  preach,  we  may  lecture,  we  may  coax,  wheedle, 


68  SCIENCE  IN  SHORT  CHAPTERS. 

or  anathematize,  but  no  amount  of  words  of  any  kind  will 
render  a  gloomy  ill-lighted  cottage  so  attractive  as  the 
bright  bar  and  tap-room  ;  and  human  nature,  irrespective 
of  conventional  distinctions  of  rank  and  class,  always  seeks 
cheerfulness  after  a  day  of  monotonous  toil.  Fifty  years 
ago  the  middle  classes  were  accustomed  to  spend  their  even- 
ings in  taverns,  but  now  they  prefer  their  homes,  simply 
because  they  have  learned  to  make  their  homes  more  com- 
fortable and  attractive. 

We  have  not  yet  learned  how  to  supply  the  working 
millions  with  suburban  villas,  but  if  their  small  rooms  can 
be  made  bright  and  cheerful  during  the  long  evenings,  a 
most  important  step  is  made  towards  that  general  improve- 
ment of  social  habits  which  necessarily  results  from  a 
greater  love  of  home.  We  may  safely  venture  to  predict 
that  the  paraffin  lamp  will  have  as  much  influence  in 
elevating  the  domestic  character  of  the  poorer  classes  as 
the  street  lamps  have  had  in  purging  the  streets  of  our 
cities  from  the  crimes  of  darkness  that  once  infested 
them. 

A  great  deal  has  been  said  about  the  poisonous  character 
of  paraffin  works.  I  admit  that  they  have  much  to  answer 
for  in  reference  to  trout — that  the  clumsy  and  wasteful 
management  of  certain  ill-conducted  works  has  interfered 
with  the  sport  of  the  anglers  of  one  or  two  of  the  trout 
streams  of  the  United  Kingdom — but  all  the  assertions  that 
have  been  made  relative  to  injury  to  human  health  are 
quite  contrary  to  truth. 

The  fact  is  that  the  manufacture  of  mineral  oils  from 
cannel  and  shale  is  an  unusually  healthful  occupation.  The 
men  certainly  have  dirty  faces,  but  are  curiously  exempt 
from  those  diseases  which  are  most  fatal  among  the  poor. 
I  allude  to  typhus  fever,  and  all  that  terrible  catalogue  of 
ills  usually  classed  under  the  head  of  zymotic  diseases. 
This  has  been  strikingly  illustrated  in  the  Flintshire  dis- 
trict. The  very  sudden  development  of  the  oil  trade  in 
the  neighborhood  of  Leeswood  caused  that  little  village  and 
the  scattered  cottages  around  to  be  crowded  to  an  extent 
that  created  the  utmost  alarm  among  all  who  are  familiar 
with  the  results  of  such  overcrowding  in  poor,  ill-drained, 


ON  THE  SOCIAL  BENEFITS  OF  PARAFFIN.        69 

and  ill-ventilated  cottages.  Rooms  were  commonly  filled 
with  lodgers  who  economized  the  apartments  on  the  Box  and 
Cox  principle,  the  night  workers  sleeping  during  the  day, 
and  the  day  workers  during  the  night,  in  the  same  heds. 
The  extent  to  which  this  overcrowding  was  carried  in  many 
instances  is  hardly  credible. 

Mr.  R.  Platt,  who  is  surgeon  to  most  of  the  collieries 
and  oilworks  of  this,  district,  reports  that  Leeswood  has 
enjoyed  a  singular  immunity  from  typhus  and  fever — that, 
during  a  period  when  it  was  prevalent  as  a  serious  epidemic 
among  the  agricultural  population  living  on  the  slopes  of 
the  surrounding  mountains,  no  single  case  occurred  among 
the  oil-making  population  of  Leeswood,  though  its  position 
and  overcrowding  seemed  so  directly  to  court  its  visitation. 
If  space  permitted  I  might  give  further  illustrations  in  ref- 
erence to  allied  diseases. 

There  is  no  difficulty  in  accounting  for  this.  Carholic 
acid,  one  of  the  most  powerful  of  our  disinfectants,  is 
abundantly  produced  in  the  oilworks,  and  this  is  carried  by 
the  clothes  of  the  men,  and  with  the  fumes  of  the  oil,  into 
the  dwellings  of  the  workmen  and  through  all  the  atmos- 
phere of  the  neighborhood,  and  has  thereby  counteracted 
some  of  the  most  deadly  agencies  of  organic  poisons.  Be- 
sides this,  the  paraffin  oil  itself  is  a  good  disinfectant. 

Even  the  mischief  done  to  the  trout  is  more  than  coun- 
terbalanced by  the  destruction  of  those  mysterious  fungoid 
growths  which  result  from  the  admixture  of  sewage  matter 
with  the  water  of  our  rivers,  and  are  so  destructive  to  hu- 
man health  and  life.  The  carbolic  acid  and  paraffin  oil,  in 
destroying  these  as  well  as  the  trout,  are  really  acting  as 
great  purifiers  of  the  river,  so  that,  after  all,  the  only  in- 
terest that  has  suffered  is  the  sporting  interest.  This  same 
interest  has  otherwise  suffered.  The  old  haunts  of  the 
snipe  and  woodcock,  of  partridges,  hares,  and  pheasants, 
are  being  ruthlessly  and  barbarously  destroyed,  and — horri- 
ble to  relate— hundreds  of  cottages,  inhabited  by  vulgar, 
hard-handed,  thick-booted  human  beings,  are  taking  their 
place.  Churches  are  being  extended,  school-houses  and 
chapels  built ;  penny  readings,  lectures,  concerts,  etc.,  are 
in  active  operation,  and  even  drinking  fountains  are  in 


70  SCIENCE  IN  SHORT  CHAPTERS. 

course  of  construction ;  but  the  trout  have  suffered  and  the 
woodcocks  are  gone. 

We  may  thus  measure  the  good  against  the  evil  as  it 
stands  here  in  the  headquarters  of  oil-making,  and  should 
add  to  one  side  the  advantages  which  the  cheap  and  bril- 
liant light  affords — advantages  which  we  might  continue  to 
enumerate,  but  they  are  so  obvious  that  it  is  unnecessary 
to  go  further. 

There  is  one  important  and  curious  matter  which  must 
not  be  omitted.  This,  like  the  moral  and  intellectual  ad- 
vantages of  the  cheap  paraffin  light,  has  hitherto  remained 
unnoticed,  viz.,  that  the  introduction  of  mineral  oils  and 
solid  paraffin  for  purposes  of  illumination  and  lubrication 
lias  largely  increased  the  world's  supply  of  food. 

This  may  not  be  generally  obvious  at  first  sight ;  but  to 
him,  who,  like  the  writer,  has  had  many  a  supper  at  an 
Italian  osteria  with  peasants  and  carbonari,  it  is  obvious 
enough.  He  will  remember  how  often  he  has  seen  the 
lamp  that  has  lighted  himself  and  companions  to  their  sup- 
per filled  from  the  same  flask  as  supplied  the  salad  which 
formed  so  important  a  part  of  the  supper  itself.  Through- 
out the  South  of  Europe  salads  are  most  important  ele- 
ments of  national  food,  and  when  thus  abundantly  eaten 
the  oil  is  quite  necessary,  the  oil  is  also  used  for  many  of 
the  cookery  operations  where  butter  is  used  here,  and  this 
same  olive  oil  has  hitherto  been  the  chief,  and  in  some 
places  the  sole,  illuminating  agent.  The  poor  peasant  of 
the  South  looks  jealously  at  his  lamp,  and  feeds  its  stingily, 
for  it  consumes  his  richest  and  choicest  food,  and,  if  well 
supplied,  would  eat  as  much  as  a  fair-sized  baby. 

The  Russian  peasant  and  other  Northern  people  have  a 
similar  struggle  in  the  matter  of  tallow.  It  is  their  choicest 
dainty,  and  yet,  to  their  bitter  grief,  they  have  been  com- 
pelled to  burn  it.  Hundreds  and  thousands  of  tons  of  this 
and  of  olive  oil  have  been  annually  consumed  for  the  lubri- 
cation of  our  steam  engines  and  other  machines.  A  better 
time  is  approaching  now  that  paraffin  lamps  are  so  rapidly 
becoming  the  chief  illuminators  of  the  whole  civilized 
world,  superseding  the  crude  tallow  caudle  and  the  antique 
olive-oil  lamp,  while,  at  the  same  time,  the  tallow  candle  is 


ON  THE  SOCIAL  BENEFITS  OF  PARAFFIN.        71 

gradually  being  replaced  by  the  beautiful  sperm-like  parf- 
fin  candle ;  and,  in  addition  to  this,  the  greedy  engines 
that  have  consumed  so  much  of  the  olive  oil  and  the  tallow 
are  learning  to  be  satisfied  with  lubricators  made  from 
minerals  kindred  to  themselves. 

The  peasants  of  the  sunny  South  will  feed  upon  salads 
made  doubly  unctuous  and  nutritious  by  the  abundant  oil ; 
their  fried  meats,  their  pastry,  omelettes,  and  sauces  will  be 
so  much  richer  and  better  than  heretofore,  and  the  Russian 
will  enjoy  more  freely  his  well-beloved  and  necessary  tal- 
low, when  the  candle  is  made  and  the  engine  lubricated 
with  the  fat  extracted  from  coals  and  stones  which  no  hu- 
man stomach  can  envy.  I  might  travel  on  to  China  and 
tell  of  the  work  that  paraffin  and  paraffin  oils  have  yet  to 
do  among  the  many  millions  there  and  in  other  countries 
of  the  East.  The  great  wave  of  mineral  light  has  not  yet 
fairly  broken  upon  their  shores ;  but  when  it  has  once 
burst  through  the  outer  barriers,  it  will,  without  doubt, 
advance  with  great  rapidity,  and  with  an  influence  whose 
beneficence  can  scarcely  be  exaggerated. 

(The  above  was  written  in  the  early  days  of  paraffin  lamps, 
and  while  the  writer  was  engaged  in  the  distillation  of 
paraffin  oils,  etc.,  from  the  Leeswood  cannel.  These  are 
now  practically  superseded  by  American  petroleum  of  simi- 
lar composition,  but  distilled  in  Nature's  oilworks.  The 
anticipations  that  appeared  Utopian  at  the  time  of  writing 
have  aince  been  fully  realized,  or  even  exceeded,  as  the 
wholesale  price  of  mineral  oil  has  fallen  from  two  shillings 
per  gallon  to  an  average  of  about  eightpeuce,  and  lamps 
have  been  greatly  improved.  At  this  price  the  cost  of  main- 
taining a  light  of  given  power  in  an  ordinary  lamp  is  about 
equal  to  that  of  ordinary  London  gas,  if  it  were  supplied  at 
one  shilling  per  thousand  cubic  feet.  The  mineral  oil, 
being  a  fine  hydrocarbon,  does  far  less  mischief  than  gas  by 
its  combustion,  as  may  be  proved  by  warming  a  conservatory 
with  a  paraffin  stove  and  another  with  a  stove.  In  the 
latter  all  the  delicate  plants  will  be  killed;  in  the  first  they 
scarcely  suffer  at  all.  If  these  facts  were  generally  under- 
stood we  should  be  in  a  better  position  for  battle  with  the 
gas  monopolies.  The  importation  of  petroleum  to  the 


72  SCIENCE  IN  SHORT  CHAPTERS. 

United  Kingdom  during  the  first   five  months  of   1882 
amounted  to  26,297,346  gallons.) 


THE  SOLIDITY  OF  THE  EARTH. 

IN  his  opening  address  to  the  Mathematical  and  Physical 
Section  of  the  British  Association,  Sir  William  Thomson 
affirmed,  "with  almost  perfect  certainty,  that,  whatever 
may  be  the  relative  densities  of  rock,  solid  and  melted,  or 
at  about  the  temperature  of  liquefaction,  it  is,  I  think, 
quite  certain  that  cold  solid  rock  is  denser  than  hot  melted 
rock;  and  no  possible  degree  of  rigidity  in  the  crust  could 
prevent  it  from  breaking  in  pieces  and  sinking  wholly  be- 
low the  liquid  lava,"  and  that  "this  process  must  goon 
until  the  sunk  portions  of  the  crust  build  up  from  the  bot- 
tom a  sufficiently  close-ribbd  skeleton  or  frame,  to  allow 
fresh  incrustations  to  remain  bridged  across  the  now  small 
areas  of  lava-pools  or  lakes."* 

This  would  doubtless  be  the  case  if  the  material  of  the 
earth  were  chemically  homogeneous  or  of  equal  specific 
gravity  throughout,  and  if  it  were  chemically  inert  in  refer- 
ence to  its  superficial  or  atmospheric  surroundings.  But 
such  is  not  the  case.  All  we  know  of  the  earth  sbows  that 
it  is  composed  of  materials  of  varying  specific  gravities,  and 
that  the  range  of  this  variation  exceeds  that  which  is  due 
to  the  difference  between  the  theoretical  internal  heat  of 
the  earth  and  its  actual  surface  temperature. 

We  know  by  direct  experiment  that  these  materials,  when 
fused  together,  arrange  themselves  according  to  their  spe- 
cific gravities,  with  the  slight  modification  due  to  their 
mutual  diffusibilities.  If  we  take  a  mixture  of  the  solid 
elements  of  which  the  earth,  so  far  as  we  know  it,  is  com- 
posed, fused  them,  and  leave  them  exposed  to  atmospheric 
action,  what  will  occur? 

The  heavy  metals  will  sink,  the  heaviest  to  the  bottom, 

*  Nature,  vol.  xiv.  p.  429. 


THE  SOLIDITY  OF  THE  EARTH.  73 

the  lighter  metals  (i.e.,  those  that  we  call  the  metals  of  the 
earths,  because  they  form  the  basis  of  the  earth's  superficial 
crust)  will  rise  along  with  the  silicon,  etc.,  to  the  surface; 
these  and  the  silicon  will  oxidize  and  combine,  forming 
silicates,  and  with  a  sufficient  supply  of  carbonic  acid,  some 
of  them,  such  as  calcium,  magnesium,  etc.,  will  form  car- 
bonates when  the  temperature  sinks  below  that  of  the  dis- 
sociation of  such  compounds. 

The  scoria  thus  formed  will  float  upon  the  heavy  metals 
below  and  protect  them  from  cooling  by  resisting  their 
radiation;  but  if  in  the  course  of  contraction  of  this  crust 
some  fissures  are  formed  reaching  to  the  melted  metals 
below,  the  pressure  of  the  floating  solid  will  inject  the  fluid 
metal  upwards  into  these  fissures  to  a  height  corresponding 
to  the  flotation  depth  of  the  solid,  and  thus  form  metallic 
veins  permeating  the  lower  strata  of  the  crust.  I  need 
scarcely  add  that  this  would  rudely  but  fairly  represent  what 
we  know  of  the  earth. 

But  it  may  be  objected  that  I  only  describe  an  imaginary 
experiment.  This  is  true  as  regards  the  whole  of  the  ma- 
terials united  in  a  single  fusion.  Nobody  has  yet  produced 
a  complete  model  with  platinum  and  gold  in  the  centre,  and 
all  the  other  metals  arranged  in  theoretical  order  with  the 
oxidized,  silicated,  and  carboneted  crust  outside;  but  with 
a  limited  number  of  elements  this  has  been  done,  is  being 
done  daily,  on  a  scale  of  sufficient  magnitude  to  amply  re- 
fute Sir  William  Thomson's  description  of  a  fused  earth 
solidifying  from  the  centre  outwards. 

This  refutation  is  to  be  seen  in  our  blast  furnaces,  refin- 
ing furnaces,  puddling  furnaces,  Bessemer  ladles,  steel 
melting-pots,  cupels,  foundry  crucibles;  in  fact,  in  almost 
every  metallurgical  operation  down  to  the  simple  fusion  of 
lead  or  solder  in  a  plumber's  ladle,  with  its  familiar  floating 
crust  of*dross  or  oxide. 

As  an  example  I  will,  on  account  of  its  simplicity,  take 
the  open  hearth  finery  and  the  refining  of  pig-iron.  Here 
a  metallic  mixture  of  iron,  silicon,  carbon,  sulphur,  etc.,  is 
simply  fused  and  exposed  to  the  superficial  action  of  atmos- 
pheric air.  What  is  the  result? 

Oxidation  of  the  more  oxidizable  constituents  takes  place, 


74  SCIENCE  IN  SHORT  CHAPTERS. 

and  these  oxides  at  once  arrange  themselves  according  to 
their  specific  gravities.  The  oxidized  carbon  forms  atmos- 
pheric matter  and  rises  above  all  as  carbonic  acid,  then  the 
oxidized  silicon,  being  lighter  than  the  iron,  floats  above 
that,  and  combines  with  aluminium  or  calcium  that  may 
have  been  in  the  pig  and  with  some  of  the  iron;  thus  form- 
ing a  silicious  crust  closely  resembling  the  predominating 
material  of  the  earth's  crust. 

When  the  oxidation  in  the  finery  is  carried  far  enough, 
the  melted  material  is  tapped  out  into  a  rectangular  basin 
or  mould,  usually  about  10  feet  long  and  about  3  feet  wide, 
where  it  settles  and  cools.  During  this  cooling  the  silica- 
and  silicates — i.e.,  the  rock  matter — separate  from  the  me- 
tallic matter  and  solidify  on  the  surface  as  a  thin  crust, 
which  behaves  in  a  very  interesting  and  instructive  manner. 
At  first  a  mere  skin  is  formed.  This  gradually  thickens, 
and  as  it  thickens  and  cools  becomes  corrugated  into  moun- 
tain chaines  and  valleys  much  higher  and  deeper,  in  pro- 
portion to  the  whole  mass,  than  the  mountain  chains  and 
valleys  of  our  planet.  After  this  crust  has  thickened  to  a 
certain  extent  volcanic  action  commences.  Eifts,  dykes, 
and  faults  are  formed  by  the  shrinkage  of  the  metal  below, 
and  streams  of  lava  are  ejected.  Here  and  there  these  lava 
streams  accumulate  around  their  vent  and  form  insolated 
conical  volcanic  mountains  with  decided  craters,  from  which 
the  eruption  continues  for  some  time.  These  volcanoes  are 
relatively  far  higher  than  Chimborazo.  The  magnitude  of 
these  actions  varies  with  the  quality  of  the  pig-iron. 

The  open  hearth  finery  is  now  but  little  used,  but  prob- 
ably some  are  to  be  seen  at  work  occasionally  in  the  neigh- 
borhood of  Glasgow,  and  I  am  sure  that  Sir  William 
Thomson  will  find  a  visit  to  one  of  them  very  intresting. 
Failing  this,  he  may  easily  make  an  experiment  by  tapping 
into  a  good-sized  "cinder  bogie"  some  melted  pig-iron  from 
a  pudding  furnace  (taking  it  just  before  the  iron  "comes 
to  nature"),  and  leaving  the  melted  mixture  to  cool  slowly 
and  undisturbed. 

The  cinder  of  the  blast  furnace,  which  in  like  manner 
floats  on  the  top  of  the  melted  pig-iron,  resembles  still  more 
closely  the  prevailing  rock-matter  of  the  earth,  on  account 


ELECTRIC  LIGHTING.  75 

of  the  larger  proportion,  and  the  varied  compounds,,  of 
earth-metals  it  contains. 

For  the  volcanic  phenomena  alone  he  need  simply  watch 
what  occurs  when  in  the  ordinary  course  of  puddling  the 
cinder  is  run  into  a  large  bogie,  and  the  bogie  is  left  to 
cool  standing  upright.  I  need  scarcely  add  that  these  phe- 
nomena strikingly  illustrate  and  confirm  Mr.  Mallett's  the- 
ory of  earthquakes,  volcanoes,  and  mountain-formation. 

In  merely  passing  through  an  iron-making  district  one 
may  see  the  results  of  what  I  have  called  the  volcanic  action, 
by  simply  observing  the  form  of  those  oyster-shaped  or 
cubical  blocks  of  cinder  that  are  heaped  in  the  vicinity  of 
every  blast  furnace  that  has  been  at  work  for  some  time. 
Radial  ridges  or  consolidated  miniature  lava-streams  are 
visible  on  the  exposed  face  of  nearly,  if  not  quite  all  of 
these.  They  were  ejected  or  squeezed  up  from  below  while 
the  mass  was  cooling,  when  the  outer  crust  had  consolidated 
but  the  inner  portion  still  remained  liquid.  Many  of  these 
are  large  enough,  and  sufficiently  well-marked,  to  be  visible 
from  a  railway  carriage  passing  a  cinder  heap  near  the 
road.* 


A      CONTRIBUTION      TO     THE      HISTORY     OF 
ELECTRIC     LIGHTING. 

As  the  subject  of  lighting  by  electricity  is  occupying  so 
much  public  attention,  and  the  merits  of  various  inventors 
and  inventions  are  so  keenly  discussed,  the  following  facts 
may  have  some  historical  interest  in  connection  with  it. 

In  October,  1845,  I  was  consulted  by  some  American 
gentlemen  concerning  the  construction  of  a  large  voltaic 
battery  for  experimenting  upon  an  invention,  afterwards 
described  and  published  in  the  specification  of  "King's 
Patent  Electric  Light '  (Letters  Patent  granted  for  Scotland, 
November  26,  1845 ;  enrolled  March  25,  1846 ;  English 
Patent  sealed  November  4,  1845). 

*  See  Chapter  on  "  The  Origin  of  Lunar  Volcanoes." 


76  SCIENCE  IN  SHORT  CHAPTERS. 

Mr.  King  was  not  the  inventor,  but  he  and  Mr.  Dorr 
supplied  capital,  and  Mr.  Snyder  also  held  a  share,  which 
was  afterwards  transferred  to  myself.  The  inventor  was 
Mr.  Starr,  a  young  man  about  twenty-five  years  of  age,  and 
one  of  the  ablest  experimental  investigators  with  whom  I 
have  ever  had  the  privilege  of  near  acquaintance. 

He  had  been  working  for  some  years  on  the  subject, 
commencing  with  the  ordinary  arc  between  charcoal  points. 
His  first  efforts  were  directed  to  maintaining  constancy,  and 
he  showed  me,  in  January  of  1846,  an  arrangement  by 
which  he  succeeded  in  effecting  an  automatic  renewal  of 
contact  by  means  of  an  electro-magnet,  the  armature  of 
which  received  the  electric  flow,  ^when  the  arc  was  broken, 
and  which  thus  magnetized  brought  the  carbons  together 
and  then  allowed  them  to  be  withdrawn  to  their  required 
separation,  when  the  flow  returned.  This  device  was  almost 
identical  with  that  subsequently  re-invented  and  patented 
by  Mr.  Staite  (quite  independently,  I  believe),  and  which, 
with  modifications,  has  since  been  rather  extensively 
used. 

Although  successful  so  far,  he  was  not  satisfied.  He 
reasoned  out  the  subject,  and  concluded  that  the  electric 
spark  between  metals,  the  electric  arc  between  the  carbons, 
and  other  luminous  electric  phenomena  are  secondary  effects 
due  to  the  heating  and  illumination  of  electric  carriers ;  that 
the  electric  spark  of  the  conductors  of  ordinary  electrical 
machines  is  simply  a  transfer  of  incandescent  particles  of 
metal,  which  effect  a  kind  of  electric  convection,  known  as 
the  disruptive  discharge  ;  and  that  the  more  brilliant  arc 
between  the  carbon  points  is  simply  due  to  the  use  of  a  sub- 
stance which  breaks  up  more  readily,  and  gives  a  longer, 
broader,  and  more  continuous  stream  of  incandescent  con- 
vection particles. 

This  is  now  readily  accepted,  but  at  that  time  was  only 
dawning  upon  the  understanding  of  electricians.  I  am  sat- 
isfied that  Mr.  Starr  worked  out  the  principle  quite  origin- 
ally. He  therefore  concluded  that,  the  light  being  due  to 
solid  particles  heated  by  electric  disturbance,  it  would  be 
more  advantageous — as  regards  steadiness,  economy,  and 
simplicity — to  place  in  the  current  a  continuous  solid  bax- 


ELECTRIC  LIGHTING.  77 

rier,  which  should  present  sufficient  resistance  to  its  passage 
to  become  bodily  incandescent  without  disruption. 

This  was  the  essence  of  the  invention  specified  in  King's 
Patent  as  "  a  communication  from  abroad,"  which  claims  the 
use  of  continuous  metallic  and  carbon  conductors,  intensely 
heated  by  the  passage  of  a  current  of  electricity,  for  the 
purposes  of  illumination. 

The  metal  selected  was  platinum,  which,  as  the  specifi- 
cation states,  "though  not  so  infusible  as  iridium,  has  but 
little  affinity  for  oxygen,  and  offers  a  great  resistance  to  the 
passage  of  the  current."  The  form  of  thin  sheets  known 
by  the  name  of  leaf-platinum  is  described  as  preferable. 
These  to  be  rolled  between  sheets  of  copper  in  order  to  secure 
uniformity,  and  to  be  carefully  cut  in  strips  of  equal  width, 
and  with  a  clean  edge,  in  order  that  one  part  may  not  be 
fused  before  the  other  parts  have  obtained  a  sufficiently  high 
temperature  to  produce  a  brilliant  light.  This  strip  to  be 
suspended  between  forceps. 

I  need  not  describe  the  arrangement  for  regulating  the 
distance  between  the  forceps,  for  directing  the  current,  etc., 
as  we  soon  learned  that  this  part  of  the  invention  was  of  no 
practical  value,  on  account  of  the  narrow  margin  between 
efficient  incandescence  and  the  fusion  of  the  platinum. 
The  experiments  with  the  large  battery  that  I  made — con- 
sisting of  100  Dauiell  cells,  with  two  square  feet  of  working 
surface  of  each  element  in  each  cell,  and  the  copper-plates 
about  three-quarters  of  an  inch  distant  from  the  zinc — 
satisfied  all  concerned  that  neither  platinum  nor  any 
available  alloy  of  platinum  and  iridium  could  be  relied 
upon  ;  especially  when  the  grand  idea  of  subdividing  the 
light  by  interposing  several  platinum  strips  in  the  same 
circuit,  and  working  with  a'  proportionally  high  power,  was 
carried  out. 

This  drove  Mr.  Starr  to  rely  upon  the  second  part  of  the 
specification,  viz.,  that  of  using  a  small  stick  of  carbon  made 
incandescent  in  a  Torricellian  vacuum.  He  commenced 
with  plumbago,  and,  after  trying  many  other  forms  of  car- 
bon, found  that  which  lines  gas-retorts  that  have  been  long 
in  use  to  be  the  best. 

The  carbon  stick  of  square  section,  about  one  tenth  of 


78  SCIESCE  AY  SHORT  CHAPTERS. 

an  inch  thick  and  half  an  inch  working  length,  was  held 
vertically,  by  metallic  forceps  at  each  end,  in  a  barometer 
tu-be,  the  upper  part  of  which,  containing  the  carbon,  was 
enlarged  to  a  sort  of  oblong  bulb.  A  tKick  platinum  wire 
from  the  upper  forceps  was  sealed  into  the  top  of  the  tube 
and  projected  beyond  ;  a  similar  wire  passed  downwards 
from  the  lower  forceps,  and  dipped  into  the  mercury  of  the 
tube,  which  was  so  long  that  when  arranged  as  a  barometer 
the  enlarged  end  containing  the  carbon  was  vacuous. 

Considerable  difficulty  was  at  first  encountered  in  sup- 
porting this  fragile  stick.  Metallic  supports  were  not  avail- 
able, on  account  of  their  expansion ;  and,  finally,  little 
cylinders  of  porcelain  were  used,  one  on  each  side  of  the 
carbon  stick,  and  about  three  eighths  of  an  inch  distant. 

By  connecting  the  mercury  cup  with  one  terminal  of  the 
battery,  and  the  upper  platinum-wire  with  the  other,  a 
brilliant  and  perfectly  steady  light  was  produced,  not  so 
intense  as  the  ordinary  disruption  arc  between  carbons,  but 
equally  if  not  more  effective,  on  account  of  the  magnitude 
of  brilliant  radiating  surface. 

Some  curious  phenomena  accompanied  this  illumination 
of  the  carbon.  The  mercury  column  fell  to  about  half  its 
barometric  height,  and  presently  the  glass  opposite  the 
carbon  stick  became  slightly  dimmed  by  the  deposition  of 
a  thin  film  of  sooty  deposit. 

At  first  the  depression  of  the  mercury  was  attributed  to 
the  formation  of  mercurial  vapor,  and  is  described  accord- 
ingly in  the  specification;  but  further  observation  refuted 
this  theory,  for  no  return  of  the  mercury  took  place  when 
the  tube  was  cooled.  The  depression  was  permanent. 
The  formation  of  vaporous  carbon  was  suggested  by  one  of 
the  capitalists;  but  neither  Mr.  Starr  nor  myself  was  satis- 
fied with  this,  nor  with  any  other  surmise  we  were  able  to 
make  during  Mr.  Starr's  lifetime,  nor  up  to  the  period  of 
final  abandonment  of  the  enterprise. 

When  this  occurred  the  remaining  apparatus  was  as- 
signed to  me,  and  I  retained  possession  of  the  finally  ar- 
ranged tube  and  carbon  for  many  years,  and  have  shown  it 
in  action  worked  by  a  small  Grove's  battery  in  the  Town 


ELECTRIC  LIGHTING.  79 

Hall  of  Birmingham,  and  many  times  to  my  pupils  at  the 
Birmingham  and  Midland  Institute. 

These  exhibitions  suggested  an  explanation  of  the  mys- 
terious gaseous  matter,  which  I  believe  to  be  the  correct 
one,  and  also  of  the  carbon  deposit.  It  is  this: — That  the 
carbon  contains  occluded  oxygen;  that  when  the  carbon  is 
heated  some  of  this  oxygen  combines  with  the  carbon,  form- 
ing carbonic  oxide  and  carbonic  acid,  and  a  little  smoke. 
I  proved  the  presence  of  carbonic  acid  by  the  usual  tests, 
but  did  not  quantitatively  determine  its  proportion  of  the 
total  atmosphere. 

If  I  were  fitting  up  another  tube  on  this  principle  I 
should  wash  it  with  a  strong  solution  of  caustic  potash  be- 
fore filling  with  mercury,  and  allow  some  of  the  potash  so- 
lution to  float  on  the  mercury  surface,  by  filling  the  tube 
while  the  glass  remained  moistened  with  the  solution.  My 
object  would  be  to  get  rid  of  the  carbonic  acid  as  soon  as 
formed,  as  the  observations  I  have  made  lead  me  to  believe 
that — when  the  carbon  stick  is  incandescent  in  an  atmos- 
phere of  carbonic  acid  or  carbonic  oxide — a  certain  degree 
of  dissociation  and  re-combination  is  continually  occurring, 
which  weakens  and  would  ultimately  break  up  the  carbon 
stick,  and  increases  the  sooty  deposit. 

The  large  battery  was  arranged  for  intensity,  but  even 
then  it  was  found  that  the  quantity  (I  use  the  old-fashioned 
terms)  of  electricity  was  excessive,  and  that  it  worked  more 
advantageously  when  the  cells  were  but  partially  filled  with 
acid  and  sulphate.  A  larger  stick  of  carbon  might  have 
been  used  with  the  whole  surface  in  full  action. 

After  working  the  battery  in  various  ways,  and  duly  con- 
sidering the  merits  of  the  other  forms  of  battery  then  in 
use,  Mr.  Starr  was  driven  to  the  conclusion  that  for  the 
purposes  of  practical  illumination  the  voltaic  battery  is  a 
hopeless  source  of  power,  and  that  magneto-electric  ma- 
chinery driven  by  steam-power  must  be  used.  I  fully  con- 
curred with  him  in  this  conclusion,  so  did  Mr.  King,  Mr. 
Dorr,  and  all  concerned. 

Mr.  Starr  then  set  to  work  to  devise  a  suitable  dynamo- 
electric  machine,  and,  following  his  usual  course  of  starting 
from  first  principles,  concluded  that  all  the  armatures 


80  SCIENCE  IN  SHORt  CHAPTERS. 

hitherto  constructed  were  defective  in  one  f undamental  ele- 
ment of  their  arrangement.  The  thick  copper  wire  sur- 
rounding the  soft  iron  core  necessarily  follows  a  spiral 
course,  like  that  of  a  coarse  screw-thread;  but  the  electric 
current  or  lines  of  force,  which  it  is  designed  to  pick  up 
and  carry,  circulate  at  right  angles  to  the  axis  of  the  core, 
and  extend  to  some  distance  beyond  its  surface.  The  prob- 
lem thus  presented  is  to  wind  around  the  soft  iron  a  con- 
ductor that  shall  be  broad  enough  to  grasp  a  large  propor- 
tion of  this  outspread  force,  and  yet  shall  follow  its  course 
as  nearly  as  possible  by  standing  out  at  right  angles  to  the 
axis  of  the  armature.  This  he  endeavored  to  effect  by  using 
a  core  of  square  section,  and  winding  round  it  a  broad  rib- 
bon of  sheet  copper,  insulated  on  both  sides  by  cementing 
on  its  surfaces  a  layer  of  silk  ribbon.  This  armature  was 
laid  with  one  edge  against  one  side  of  the  core,  and  carried 
on  thus  to  the  angle;  then  turned  over  so  that  its  opposite 
edge  should  be  presented  to  the  next  side  of  the  core;  this 
side  to  be  followed  in  like  manner,  the  ribbon  similarly 
turned  again  at  the  next  corner,  and  so  on  till  the  core  be- 
came fully  enclosed  or  armed  with  the  continuous  ribbon, 
which  thus  encircled  the  core  with  its  edges  outwards,  and 
nearly  at  right  angles  to  the  axis,  in  spite  of  its  width, 
which  might  be  increased  to  any  extent  found  by  experi- 
ment to  be  desirable. 

At  this  stage  my  direct  co-operation  and  confidential 
communication  with  Mr.  Starr  ceased,  as  I  remained  in 
London  while  he  went  to  Birmingham  in  order  to  get  his 
machinery  constructed,  and  to  apply  it  at  the  works  of 
Messrs.  Elkington,  who  had  then  recently  introduced  the 
principle  of  dynamo-electric  motive-power  for  electro-plat- 
ing, etc.,  and  were,  I  believe,  using  Woolriclrs  apparatus, 
the  patent  for  which  was  dated  August  1,  1842,  and  en- 
rolled February  1,  1843. 

I  am  unable  to  state  the  results  of  his  efforts  in  Birming- 
ham. I  only  heard  the  murmurs  of  the  capitalists,  who 
loudly  complained  of  expenditure  without  results.  They 
had  dreamed  the  same  dream  that  Mr.  Edison  has  recently 
re- dreamed,  and  has  told  the  world  so  loudly.  They  sup- 
posed that  the  mechanically  excited  current  might  be  car- 


ELECTRIC  LIGHTING.  81 

ried  along  great  lengths  of  wire,  and  the  carbons  interposed 
wherever  required,  and  that  the  same  electricity  would  flow 
on  and  do  the  duty  of  illumination  over  and  over  again  as 
a  river  may  fall  over  a  succession  of  weirs  and  turn  water- 
wheels  at  each.  Mr.  Starr  knew  better  ;  his  scepticism 
was  misinterpreted  ;  he  was  taunted  with  failure  and  non- 
fulfilment  of  the  anticipations  he  had  raised,  and  with  the 
fruitless  expenditure  of  large  sums  of  other  people's  money. 
He  was  a  high-minded,  honorable,  and  very  sensitive  mail, 
suffering  already  from  overworked  brain  before  he  went  to 
Birmingham.  There  he  worked  again  still  harder,  with 
further  vexation  and  disappointment,  until  one  morning 
he  was  found  dead  in  his  bed.  Having,  during  my  short 
acquaintance  with  him,  enjoyed  his  full  confidence  in  ref- 
erence to  all  his  investigations,  I  have  no  hesitation  in 
affirming  that  his  early  death  cut  short  the  career  of  one 
who  otherwise  would  have  largely  contributed  to  the  pro- 
gress of  experimental  science,  and  have  done  honor  to  his 
country. 

His  martyrdom,  for  such  it  was,  taught  me  a  useful  les- 
son I  then  much  needed,  viz.,  to  abstain  from  entering 
upon  a  costly  series  of  physical  investigations  without  being 
well  assured  of  the  means  of  completing  them,  and,  above 
all,  of  being  able  to  afford  to  fail. 

There  are  many  others  who  sorely  need  to  be  impressed 
with  the  same  lesson,  especially  at  this  moment  and  in  con- 
nection with  this  subject. 

The  warning  is  the  most  applicable  to  those  who  are  now 
misled  by  a  plausible  but  false  analogy.  They  look  at  the 
progress  made  in  other  things,  the  mighty  achievements  of 
modern  Science,  and  therefore  infer  that  the  electric  light 
— even  though  unsuccessful  hitherto — may  be  improved  up 
to  practical  success,  as  other  things  have  been.  A  great 
fallacy  is  hidden  here.  As  a  matter  of  fact  the  progress 
made  in  electric  lighting  since  Mr.  Starr's  death,  in  1846, 
has  been  very  small  indeed.  As  regards  the  lamp  itself  no 
progress  whatever  has  been  made.  I  am  satisfied  that 
Starr's  continuous  carbon  stick,  properly  manoged  in  a  true 
vacuum,  or  an  atmosphere  free  from  oxygen,  carbonic 
oxide,  carbonic  acid,  or  other  oxygen  compound,  is  the  best 


82  SCIENCE  IN  SHORT  CHAPTERS. 

that  has  yet  been  placed  before  the  public  for  all  purposes 
where  exceptionally  intense  illumination  (as  in  lighthouses) 
is  not  demanded.* 

Comparing  electric  with  gas-lighting,  the  hopeful  be- 
lievers in  progressive  improvement  appear  to  forget  that 
gas- making  and  gas-lighting  are  as  susceptible  of  further 
improvement  as  electric  lighting,  and  that,  as  a  matter  of 
fact,  its  practical  progress  during  the  last  forty  years  is  in- 
comparably greater  than  that  of  the  electric  light.  I  refer 
more  particularly  to  the  practical  and  crucial  question  of 
economy.  The  bi-products,  the  ammoniacal  salts,  the 
liquid  hydrocarbons,  and  their  derivatives,  have  been 
developed  into  so  many  useful  forms  by  the  achievements 
of  modern  chemistry,  that  these,  with  the  coke,  are  of 
sufficient  value  to  cover  the  whole  cost  of  manufacture, 
and  leave  the  gas  itself  as  a  volatile  residuum  that  costs 
nothing.  It  would  actually  and  practically  cost  nothing, 
and  might  be  profitably  delivered  to  the  burners  of  gas 
consumers  (of  far  better  quality  than  now  supplied  in 
London)  at  one  shilling  per  thousand  cubic  feet,  if  gas- 
making  were  conducted  on  sound  commercial  principles, — 
that  is,  if  it  were  not  a  corporate  monopoly,  and  were  sub- 
ject to  the  wholesome  stimulating  influence  of  free  compe- 
tition and  private  enterprise.  As  it  is,  our  gas  and  the 
price  we  pay  for  it  are  absurdities  ;  and  all  calculations 
respecting  the  comparative  cost  of  new  methods  of  illumi- 
nation should  be  based  not  on  what  we  do  pay  per  candle- 
power  of  gas-light,  but  what  we  ought  to  pay  and  should 
pay  if  the  gas  companies  were  subjected  to  desirable  compe- 
tition, or  visited  with  the  national  confiscation  I  consider 
they  deserve. 

Having  had  considerable  practical  experience  in  the 
commercial  distillation  of  coal  for  the  sake  of  its  liquid 

*The  burnt  card,  burnt  bamboo,  and  other  flimsy  incandescent 
threads  now  (1883)  in  vogue,  merely  represent  Starr's  preliminary 
failures  prior  to  his  adoption  of  the  hard  adamantine  stick  of  retort- 
carbon,  which  I  suppose  will  be  duly  re-invented,  patented  again, 
and  form  the  basis  of  new  Limited  Companies,  when  the  present 
have  collapsed. 


ELECTRIC  LIGHTING.  83 

and  solid  hydrocarbons,  I  speak  thus  plainly  and  with  full 
confidence. 

There  is  yet  another  consideration,  and  one  of  vital  im- 
portance, to  be  taken  into  account,  viz.,  that — whether  we 
use  the  electric  light  derived  from  a  dynamo-electric  source, 
or  coal-gas — our  primary  source  of  illuminating  power  is 
coal,  or  rather  the  chemical  energy  derivable  from  the  com- 
bination of  its  hydrogen  and  carbon  with  oxygen.  Now 
this  chemical  energy  is  a  limited  quantity,  and  the  progress 
of  Science  can  no  more  increase  this  quantity  than  it  can 
make  a  ton  of  coal  weigh  21  cwts.  by  increasing  the  quan- 
tity of  its  gravitating  energy. 

The  demonstrable  limit  of  scientific  possibilities  is  the 
economical  application  of  this  limited  store  of  energy,  by 
converting  it  into  the  demanded  form  of  force  without 
waste.  The  more  indirect  and  roundabout  the  method  of 
application,  the  greater  must  be  the  loss  of  power  in  the 
course  of  its  transfer  and  conversion.  In  heating  the  boiler 
that  sets  the  dynamo-electric  machine  to  work,  about  one- 
half  the  energy  of  the  coal  Is  wasted,  even  with  the  best 
constructed  furnaces.  This  merely  as  regards  the  quantity 
of  water  evaporated.  In  converting  the  heat-force  into 
mechanical  power — raising  the  piston,  etc.,  of  the  steam- 
engine — this  working  half  is  again  seriously  reduced.  In 
further  converting  this  residuum  of  mechanical  power  into 
electrical  energy,  another  and  considerable  loss  is  suffered 
in  originating  and  sustaining  the  motion  of  the  dynamo- 
electric  machine,  in  the  dissipation  of  the  electric  energy 
that  the  armature  cannot  pick  up,  and  in  overcoming  the 
electrical  resistances  to  its  transfer. 

I  am  unable  to  state  the  amount  of  this  loss  in  trust- 
worthy figures,  but  should  be  very  much  surprised  to  learn 
that,  with  the  best  arrangements  now  known,  more  than 
one-tenth  of  the  original  energy  of  the  coal  is  made  practi- 
cally available.  This  small  illuminating  residuum  may,  and 
doubtless  will,  be  increased  by  the  progress  of  practical 
improvement;  but  from  the  necessary  nature  of  the  prob- 
lem, the  power  available  for  illumination  at  the  end  of  the 
series  must  always  be  but  a  small  portion  of  that  employed 
at  the  beginning. 


84  SCIENCE  IN  BHORT  CHAPTERS. 

In  burning  the  gas  derived  from  coal  we  obtain  its 
illuminating  power  directly,  and  if  we  burn  it  properly 
we  obtain  nearly  all.  The  coke  residuum  is  also  directly 
used  as  a  source  of  heat.  The  chief  waste  of  the  original 
energy  in  the  gas-works  is  represented  by  that  portion  of 
the  coke  that  is  burned  under  the  retorts,  and  in  obtaining 
the  relatively  small  amount  of  steam-power  demanded  in 
the  works.  These  are  far  more  than  paid  for  by  the  value 
of  the  liquid  hydrocarbons  and  the  ammonia  salts,  when 
they  are  properly  utilized. 

In  concluding  my  narrative,  I  may  add  that  after  Mr. 
Starr's  death  the  patentees  offered  to  engage  me  on  certain 
terms  to  carry  on  his  work.  I  declined  this,  simply  be- 
cause I  had  seen  enough  to  convince  me  of  the  impossi- 
bility of  any  success  at  all  corresponding  to  their  anticipa- 
tions. During  the  intervening  thirty  years  I  have  abstained 
from  further  meddling  with  the  electric  light,  because  all 
that  I  had  seen  then,  and  have  heard  of  since,  has  con- 
vinced me  that — although  as  a  scientific  achievement  the 
electric  light  is  a  splendid  success — its  practical  application 
to  all  purposes  where  cost  is  a  matter  of  serious  considera- 
tion is  hopeless,  and  must  of  necessity  continue  to  be  so. 

Whoever  can  afford  to  pay  some  shillings  per  hour  for 
a  single  splendid  light  of  solar  completeness  can  have  it 
without  difficulty,  but  not  so  where  the  cost  in  pence  per 
hour  per  burner  has  to  be  counted. 

I  should  add  that  before  the  publication  of  King's 
specification,  Mr.  (now  Sir  William)  Grove  proposed  the 
use  of  a  helix  or  coil  of  platinum,  made  incandescent  by 
electricity,  as  a  light  to  be  used  for  certain  purposes. 
This  was  shown  at  the  Eoyal  Society  on  or  about  December 
1,  1845. 

Since  the  publication  of  the  above  in  1879, 1  have  learned, 
from  a  paper  in  the  "  Quarterly  Journal  of  Science,"  by 
Professor  Ayrton,  that  in  1841  an  English  patent  was 
granted  to  De  Moylens  for  electric  lighting  by  incan- 
descence. 


THE  FORMATION  OF  COAL.  85 


THE  FOKMATION  OF  COAL. 

IN  the  course  of  a  pedestrian  excursion  made  in  the 
summer  of  1855  I  came  upon  the  Aachensee,  one  of  the 
lakes  of  North  Tyrol,  rarely  visited  by  tourists.  It  is 
situated  about  30  miles  N.E.  of  Innispruck,  and  fills  the 
basin  of  a  deep  valley,  the  upper  slopes  of  which  are  steep 
and  richly  wooded.  The  water  of  this  lake  is  remarkably 
transparent  and  colorless.  With  one  exception,  that  of  the 
Fountain  of  Cyane — a  deep  pool  forming  the  source  of  the 
little  Syracusan  river — it  is  the  most  transparent  body  of 
water  I  remember  to  have  seen.  This  transparency  re- 
vealed a  very  remarkable  sub-aqueous  landscape.  The 
bottom  of  the  lake  is  strewn  with  branches  and  trunks 
of  trees,  which  in  some  parts  are  in  almost  forest-like 
profusion.  As  I  was  alone  in  a  rather  solitary  region, 
and  carrying  only  a  satchel  of  luggage,  my  only  means 
of  further  exploration  were  those  afforded  by  swimming 
and  diving.  Being  an  expert  in  these,  and  the  July  sum- 
mer day  very  calm  and  hot,  I  remained  a  long  time  in  the 
water,  and,  by  swimming  very  carefully  to  avoid  ripples, 
was  able  to  survey  a  considerable  area  of  the  interesting 
scene  below. 

The  fact  which  struck  me  the  most  forcibly,  and  at  first 
appeared  surprising,  was  the  upright  position  of  many  of 
the  large  trunks,  which  are  of  various  lengths— some  alto- 
gether stripped  of  branches,  others  with  only  a  few  of  the 
larger  branches  remaining.  The  roots  of  all  these  are  more 
or  less  buried,  and  they  present  the  appearance  of  having 
grown  where  they  stand.  Other  trunks  were  leaning  at 
various  angles  and  partly  buried,  some  trunks  and  many 
branches  lying  down. 

On  diving  I  found  the  bottom  to  consist  of  a  loamy  pow 
der  of  gray  color,  speckled  with  black  particles  of  vegetable 
matter — thin  scaly  fragments  of  bark  and  leaves.  I  brought 
up  several  twigs  and  small  branches,  and  with  considera- 
ble difficulty,  after  a  succession  of  immersions,  succeeded 
in  raising  a  branch  about  as  thick  as  my  arm  and  about 
eight  feet  long,  above  three-fourths  of  which  was  buried, 


86  '  SCIENCE  IN  SHORT  CHAPTERS. 

and  only  the  end  above  ground  in  the  water.  My  object 
was  to  examine  the  condition  of  the  buried  and  immersed 
wood,  and  I  selected  this  as  the  oldest  piece  I  could  reach. 

I  found  the  wood  very  dark,  the  bark  entirely  gone,  and 
the  annual  layers  curiously  loosened  and  separable  from 
each  other,  like  successive  rings  of  bark.  This  continued 
till  I  had  stripped  the  stick  to  about  half  of  its  original 
thickness,  when  it  became  too  compact  to  yield  to  further 
stripping. 

This  structure  apparently  results  from  the  easy  decom- 
position of  the  remains  of  the  original  cambium  of  each 
year,  and  may  explain  the  curious  fact  that  so  many  speci- 
mens of  fossilized  wood  exhibit  the  original  structure  of 
the  stem,  although  all  the  vegetable  matter  has  been  dis- 
placed by  mineral  substances.  If  this  stem  had  been  im- 
mersed in  water  capable  of  precipitating  or  depositing  min- 
eral matter  in  very  small  interstices,  the  deposit  would  have 
filled  up  the  vacant  spaces  between  these  rings  of  wood  as 
the  slow  decomposition  of  the  vegetable  matter  proceeded. 
At  a  later  period,  as  the  more  compact  wood  became  de- 
composed, it  would  be  substituted  by  a  further  deposit,  and 
thus  concentric  strata  would  be  formed,  presenting  a  mimic 
counterpart  of  the  vegetable  structure. 

The  stick  examined  appeared  to  be  a  branch  of  oak,  and 
was  so  fully  saturated  with  water  that  it  sank  rapidly  upon 
being  released. 

On  looking  around  the  origin  of  this  sub-aqueous  forest 
was  obvious  enough.  Here  and  there  the  steep  wooded 
slopes  above  the  lake  were  broken  by  long  alleys  or  down- 
ward strips  of  denuded  ground,  where  storm  torrents,  or 
some  such  agency,  had  cleared  away  the  trees  and  swept 
most  of  them  into  the  lake.  A  few  uprooted  trees  lying 
at  the  sides  of  these  bare  alleys  told  the  story  plainly  enough. 
Most  of  these  had  a  considerable  quantity  of  earth  and 
stones  adhering  to  their  roots :  this  explains  the  upright 
position  of  the  trees  in  the  lake. 

Such  trees  falling  into  water  of  sufficient  depth  to  enable 
them  to  turn  over  must  sink  root  downwards,  or  float  in  an 
upright  position,  according  to  the  quantity  of  adhering  soil. 
The  difference  of  depth  would  tend  to  a  more  rapid  pene- 


THE  FORMATION  OF  COAL.  87 

tratiou  of  water  in  the  lower  parts,  where  the  pressure  would 
be  greatest,  and  thus  the  upright  or  oblique  position  of 
many  of  the  floating  trunks  would  be  maintained  till  they 
absorbed  sufficient  water  to  sink  altogether. 

It  is  generally  assumed  that  fpssil  trees  which  are  found 
in  an  upright  position  haye  grown  on  the  spot  where  they 
are  found.  The  facts  I  have  stated  show  that  this  infer- 
ence is  by  no  means  necessary,  not  even  when  the  roots  are 
attached  and  some  soil  is  found  among  them.  In  order  to 
account  for  the  other  surroundings  of  these  fossil  trees  a 
very  violent  hypothesis  is  commonly  made,  viz.,  that  the 
soil  on  which  they  grew  sank  down  some  hundreds  of  feet 
without  disturbing  them.  This  demands  a  great  strain 
upon  the  scientific  imagination,  even  in  reference  to  the 
few  cases  where  the  trees  stand  perpendicular.  As  the 
majority  slope  considerably  the  difficulty  is  still  greater.  I 
shall  presently  show  how  trees  like  those  immersed  in 
Aachensee  may  have  become,  and  are  now  becoming,  im- 
bedded in  rocks  similar  to  those  of  the  Coal  Measures. 

In  the  course  of  subsequent  excursions  on  the  fjords  of 
Norway  I  was  reminded  of  the  sub-aqueous  forest  of  the 
Aachensee,  and  of  the  paper  which  I  read  at  the  British 
Association  meeting  of  1865,  of  which  the  above  is  an  ab- 
stract— not  by  again  seeing  such  a  deposit  under  water, 
for  none  of  the  fjords  approach  the  singular  transparency 
of  the  lake,  but  by  a  repetition  on  a  far  larger  scale  of  the 
downward  strips  of  denuded  forest  ground.  Here,  in  Nor- 
way, their  magnitude  justifies  me  in  describing  them  as 
vegetable  avalanches.  They  may  be  seen  on  the  Sognef  jord, 
and  especially  on  those  terminal  branches  of  this  great 
estuary,  of  which  the  steep  slopes  are  well  wooded.  But 
the  most  remarkable  display  that  I  have  seen  was  in  the 
course  of  the  magnificent,  and  now  easily  made,  journey  up 
the  Storfjord  and  its  extension  and  branches,  the  Slyngs- 
fjord,  Sunelvsfjord,  Nordalsfjord,  and  Geirangerfjord. 
Here  these  avalanches  of  trees,  with  their  accompaniment 
of  fragments  of  rock,  are  of  such  frequent  occurrence  that 
sites  of  the  farm-houses  are  commonly  selected  with  refer- 
ence to  possible  shelter  from  their  ravages.  In  spite  of  this 
they  do  not  always  escape.  In  the  October  previous  to  my 


88  8GIENOE  IN  SHORT  CHAPTERS. 

last  visit  a  boat-house  and  boat  were  swept  away;  and  one 
of  the  most  recent  among  the  tracks  that  I  saw  reached 
within  twenty  yards  of  some  farm-buildings. 

What  has  become  of  the  millions  of  trees  that  are  thus 
falling,  and  have  fallen,  into  the  Norwegian  fjords  during 
the  whole  of  the  present*  geological  era  ?  In  considering 
this  question  we  must  remem'ber  that  the  mountain  slopes 
forming  the  banks  of  these  fjords  continue  downwards 
under  the  waters  of  the  fjords  which  reach  to  depths  that 
in  some  parts  are  to  be  counted  in  thousands  of  feet. 

It  is  evident  that  the  loose  stony  and  earthy  matter  that 
accompanies  the  trees  will  speedily  sink  to  the  bottom  and 
rest  at  the  foot  of  the  slope  somewhat  like  an  ordinary  sub- 
aerial  talus,  but  not  so  the  trees.  The  impetus  of  their 
fall  must  launch  them  afloat  and  impel  them  towards  the 
middle  of  the  estuary,  where  they  will  be  spread  about  and 
continue  floating,  until  by  saturation  they  become  dense 
enough  to  sink.  They  will  thus  be  pretty  evenly  distrib- 
uted over  the  bottom.  At  the  middle  part  of  the  estuary 
they  will  form  an  almost  purely  vegetable  deposit,  mingled 
only  with  the  very  small  portion  of  mineral  matter  that  is 
held  in  suspension  in  the  apparently  clear  water.  This 
mineral  matter  must  be  distributed  among  the  vegetable 
matter  in  the  form  of  impalpable  particles  having  a  chem- 
ical composition  similar  to  that  of  the  rocks  around.  Near 
the  shores  a  compound  deposit  must  be  formed  consisting  of 
trees  and  fragments  of  leaves,  twigs,  and  other  vegetable 
matter  mixed  with  larger  proportions  of  the  mineral  debris. 

If  we  look  a  little  further  at  what  is  taking  place  in  the 
fjords  of  Norway  we  shall  see  how  this  vegetable  deposit 
will  ultimately  become  succeeded  by  an  overlying  mineral 
deposit  which  must  ultimately  constitute  a  stratified  rock. 

All  these  fjords  branch  up  into  inland  valleys  down  which 
pours  a  brawling  torrent  or  a  river  of  some  magnitude. 
These  are  more  or  less  turbid  with  glacier  mud  or  other 
detritus,  and  great  deposits  of  this  material  have  already 
accumulated  in  such  quantity  as  to  constitute  characteristic 
modern  geological  formations  bearing  the  specific  Norsk 
name  of  or  en,  as  Laerdalsoren,  Sundalsoren,  etc.,  describ- 
ing the  small  delta  plains  at  the  mouth  of  a  river  where  it 


TEE  FORMATION  OF  COAL.  89 

enters  the  termination  of  the  fjord,  and  which,  from  their 
exceptional  fertility,  constitute  small  agricultural  settle- 
ments bearing  these  names,  which  signify  the  river  sands 
of  Laerdal,  Sundal,  etc.  These  deposits  stretch  out  into 
the  fjord,  forming  extensive  shallows  that  are  steadily  grow- 
ing and  advancing  further  and  further  into  the  fjord.  One 
of  the  most  remarkable  examples  of  such  deposits  is  that 
brought  by  the  Storelv  (or  Justedals  Elv),  which  flows  down 
the  Justedal,  receiving  the  outpour  from  its  glaciers,  and 
terminates  at  Marifjoren.  When  bathing  here  I  found  an 
extensive  sub-aqueous  plain  stretching  fairly  across  that 
branch  of  the  Lyster  fjord  into  which  the  Storelv  flows. 
The  waters  of  the  fjord  are  whitened  to  a  distance  of  two 
or  three  miles  beyond  the  mouth  of  the  river.  These  de- 
posits must,  if  the  present  conditions  last  long  enough, 
finally  extend  to  the  body,  and  even  to  the  mouth,  of  the 
fjords,  and  thus  cover  the  whole  of  the  bottom  vegetable 
bed  with  a  stratified  rock  in  which  will  be  entombed,  and 
well  preserved,  isolated  specimens  of  the  trees  and  other 
vegetable  forms  corresponding  to  those  accumulated  in  a 
thick  bed  below,  but  which  have  been  lying  so  long  in  the 
clear  waters  that  they  have  become  sodden ed  into  homo- 
geneous vegetable  pulp.or  mud,  only  requiring  the  pressure 
of  solid  superstratum  to  convert  them  into  coal. 

The  specimens  of  trees  in  the  upper  rock,  I  need  scarcely 
add,  would  be  derived  from  the  same  drifting  as  that  which 
produced  the  lower  pulp;  but  these  coming  into  the  water 
at  the  period  of  its  turbidity  and  of  the  rapid  deposition  of 
mineral  matter,  would  be  sealed  up  one  by  one  as  the 
mineral  particles  surrounding  it  subsided.  Fossils  of  es- 
tuarine  animals  would,  of  course,"  accompany  these,  or  of 
fresh-water  animals  where,  instead  of  a  fjord,  the  scene  of 
these  proceedings  is  an  inland  lake.  In  reference  to  this  I 
may  state  that  at  the  inner  extremities  of  the  larger  Nor- 
wegian fjords  the  salinity  of  the  water  is  so  slight  that  it  is 
imperceptible  to  taste.  I  have  freely  quenched  my  thirst 
with  the  water  of  the  Sorf  jord,  the  great  inner  branch  of 
the  Hardanger,  where  pallid  specimens  of  bladder  wrack 
were  growing  on  its  banks. 

In  the  foregoing  matter-of-fact  picture  of  what  is  pro- 


90  SCIENCE  IN  8UORT  CHAPTERS. 

ceeding  on  a  small  scale  in  the  Aaehensee,  and  on  a  larger 
in  Norway,  we  have,  I  think,  a  natural  history  of  the  for- 
mation, not  only  of  coal  seams,  but  also  of  the  Coal  Meas- 
ures around  and  above  them. 

The  theory  which  attributed  our  coal  seains  to  such  vege- 
table accumulations  as  the  rafts  of  the  Mississippi  is  now 
generally  abandoned.  It  fails  to  account  for  the  state  of 
preservation  and  the  position  of  many  of  the  vegetable  re- 
mains associated  with  coal. 

There  is  another  serious  objection  to  this  theory  that  I 
have  not  seen  expressed.  It  is  this:  rivers  bringing  down 
to  their  mouths  such  vegetable  deltas  as  are  supposed, 
would  also  bring  considerable  quantities  of  earthy  matter 
in  suspension,  and  this  would  be  deposited  with  the  trees. 
Instead  of  the  2  or  3  per  cent  of  incombustible  ash  com- 
monly found  in  coal,  we  should  thus  have  a  quantity  more 
nearly  like  that  found  in  bituminous  shales  which  may  thus 
be  formed,  viz.,  from  20  to  80  per  cent. 

The  alternative  hypothesis  now  more  commonly  accepted 
— that  the  vegetation  of  our  coal-fields  actually  grew  where 
we  find  it — is  also  refuted  by  the  composition  of  coal-ash. 
If  the  coal  consisted  simply  of  the  vegetable  matter  of  buried 
forests  its  composition  should  correspond  to  that  of  the 
ashes  of  plants;  and  the  refuse  from  our  furnaces  and  fire- 
places would  be  a  most  valuable  manure.  This  we  know 
is  not  the  case.  Ordinary  coal-ash,  as  Bischof  has  shown, 
nearly  corresponds  to  that  of  the  rocks  with  which  it .  is 
associated;  and  he  says  that  "the  conversion  of  vegetable 
substances  into  coal  has  been  effected  by  the  agency  of 
water;"  and  also  that  coal  has  been  formed,  not  from  dwarf- 
ish mosses,  sedges,  and  other  plants  which  now  contribute 
to  the  growth  of  our  peat-bogs,  but  from  the  stems  and 
trunks  of  the  forest  trees  of  the  Carboniferous  Period, 
such  as  Sigittarm,  Lepdodendra,  and  Coniferm.*  All  we 
know  of  these  plants  teaches  us  that  they  could  not  grow 
in  a  merely  vegetable  soil  containing  but  2  or  3  per  cent  of 
mineral  matter.  Such  must  have  been  their  soil  for  hun- 
dreds of  generations  in  order  to  give  a  depth  sufficient  for 
the  formation  of  the  South  Staffordshire  ten-yard  seam. 

*  Hull,  "  On  the  Coal-fields  of  Great  Britain." 


THE  FORMATION  OF  COAL.  91 

All  these  and  other  difficulties  that  have  stood  so  long 
in  the  way  of  a  satisfactory  explanation  of  the  origin  of 
coal  appear  to  me  to  be  removed  if  we  suppose  that  during 
the  Carboniferous  Period  Britain  and  other  coal-bearing 
countries  had  a  configuration  similar  to  that  which  now 
exists  in  Norway,  viz.,  inland  valleys  terminating  in  marine 
estuaries,  together  which  inland  lake  basins.  If  to  this  we 
superadd  the  warm  and  humid  climate  usually  attributed 
to  the  Carboniferous  Period,  on  the  testimony  of  its  vege- 
table fossils,  all  the  conditions  requisite  for  producing 
the  characteristic  deposits  of  the  Coal  Measures  are  ful- 
filled. 

We  have  first  the  under-clay  due  to  the  beginning  of  this 
state  of  things,  during  which  the  hill  slopes  were  slowly 
acquiring  the  first  germs  of  subsequent  forest  life,  and  were 
nursing  them  in  their  scanty  youth.  This  deposit  would 
be  a  mineral  mud  with  a  few  fossils  and  that  fragmentary 
or  fine  deposit  of  vegetable  matter  that  darkens  the  carbo- 
niferous shales  and  strips  the  sandstones.  Such  a  bed  of 
dark  consolidated  mud,  or  fine  clay,  is  found  under  every 
seam  of  coal,  and  constitutes  the  "floor"  of  the  coal  pit. 
The  characteristic  striped  rocks — the  "linstey"  or  "linsey" 
of  the  Welsh  colliers — is  just  such  as  I  found  in  the  course 
of  formation  in  the  Aachensee  near  the  shore,  as  described 
above. 

The  prevalence  of  estuarine  and  lacustrine  fossils  in  the 
Coal  Measures  is  also  in  accordance  with  this:  the  constitu- 
tion of  coal-ash  is  perfectly  so.  Its  extreme  softness  and 
fineness  of  structure;  its  chemical  resemblance  to  the  rocks 
around,  and  above,  and  below;  and  oblong  basin  form  com- 
mon to  our  coal  seams;  the  apparent  contradiction  of  such 
total  destruction  of  vegetable  structure  common  to  the  true 
coal  seams,  while  immediately  above  and  below  them  are 
delicate  structures  well  preserved,  is  explained  by  the  more 
rapid  deposition  of  the  latter,  and  the  slow  soddening  of 
the  former  as  above  described. 

I  do  not,  however,  offer  this  as  an  explanation  of  the  for- 
mation of  every  kind  of  coal.  On  the  contrary,  I  am  satis- 
fied that  cannel  coal,  and  the  black  shales  usually  associated 
with  it,  have  a  different  origin  from  that  of  the  ordinary 


92  SCIENCE  IN  SHORT  CHAPTERS. 

varieties  of  bituminous  coal.  The  fact  that  the  products  of 
distillation  of  cannel  and  these  shales  form  different  series  of 
hydrocarbons  from  those  of  common  coal,  and  that  they 
are  nearly  identical  with  those  obtained  by  the  distillation 
of  peat,  is  suggestive  of  origin  in  peat-bogs,  or  something 
analogous  to  them. 

To  the  above  I  may  add  the  concluding  sentences  of  the 
chapter  on  Coal  in  Lyell's  "Elements of  Geology."  Speak- 
ing of  fossils  in  the  Coal  Measures,  he  says:  "The  rarity  of 
air-breathers  is  a  very  remarkable  fact  when  we  reflect  that 
our  opportunities  of  examining  strata  in  close  connection 
with  ancient  land  exceed  in  this  case  all  that  we  enjoy  in 
regard  to  any  other  formations,  whether  primary,  secondary, 
or  tertiary.  We  have  ransacked  hundreds  of  soils  replete 
with  the  fossil  roots  of  trees,  have  dug  out  hundreds  of 
erect  trunks  and  stumps  which  stood  in  the  position  in 
which  they  grew,  have  broken  up  myriads  of  cubic  feet  of 
fuel  still  retaining  its  vegetable  structure,  and,  after  all,  we 
continue  almost  as  much  in  the  dark  respecting  the  inver- 
tebrate air-breathers  of  this  epoch,  as  if  the  coal  had  been 
thrown  down  in  mid-ocean.  The  early  date  of  the  carbo- 
niferous strata  cannot  explain  the  enigma,  because  we  know 
that  while  the  land  supported  a  luxuriant  vegetation,  the 
contemporaneous  seas  swarmed  with  life — with  Articulata, 
Mollusca,  Kadiata,  and  Fishes.  We  must,  therefore,  collect 
more  facts  if  we  expect  to  solve  a  problem  which,  in  the 
present  state  of  science,  cannot  but  excite  our  wonder;  and 
we  must  remember  how  much  the  conditions  of  this  problem 
have  varied  within  the  last  twenty  years.  We  must  be  con- 
tent to  impute  the  scantiness  of  our  data  and  our  present 
perplexity  partly  to  our  want  of  diligence  as  collectors,  and 
partly  to  our  want  of  skill  as  interpreters.  We  must  also 
confess  that  our  ignorance  is  great  of  the  laws  which  govern 
the  fossilization  of  land  animals,  whether  of  low  or  high 
degree." 

The  explanation  of  the  origin  of  coal  which  I  have  given 
in  the  foregoing  meets  all  these  difficulties.  It  shows  how 
vast  accumulations  of  vegetable  matter  may  have  been 
formed  "in  close  connection  with  the  ancient  land,"  and 
yet  "  as  if  the  coal  had  been  thrown  down  in  mid-ocean"  as 


THE  SOLAR  ECLIPSE  OF  1871.  93 

far  as  the  remains  of  terrestrial  animals  are  concerned.  It 
explains  the  nearly  total  absence  of  land  shells,  and  of  the 
remains  of  other  animals  that  must  have  lived  in  the  forests 
producing  the  coal,  and  which  would  have  heen  buried 
there  with  the  coal  had  it  been  formed  on  land  as  usually 
supposed.  It  also  meets  the  cases  of  the  rare  and  curious 
exceptions,  seeing  that  occasionally  a  land  animal  would 
here  and  there  be  drowned  in  such  fjords  under  cirum- 
stances  favorable  to  its  fossilization. 


THE     SOLAR    ECLIPSE    OF    1871. 
THE  FIEST  TELEGRAMS. 

THIS  time  we  may  fairly  expect  some  approach  to  a 
solution  of  the  riddle  of  the  corona,  as  the  one  essential 
which  neither  scientific  skill  nor  Government  liberality 
could  secure  to  the  eclipse  observers,  has  been  afforded,  viz., 
fine  weather.  The  telegraph  has  already  informed  us  of 
this,  and  also  that  good  use  has  been  made  of  the  good 
weather.  From  one  station  we  are  told:  "Thin  mist; 
spectroscope  satisfactory ;  reversion  of  lines  entirely  con- 
firmed ;  six  good  photographs."  From  another  :  "  Weather 
fine  ;  telescopic  and  camera  photographs  successful ;  ditto 
polarization  ;  good  sketches;  many  bright  lines  in  spec- 
trum." 

This  is  very  different  from  the  gloomy  accounts  of  the 
expedition  of  last  year  ;  when  we  consider  that  the  different 
observers  are  far  apart,  and  that  if  all  or  some  of  them  are 
similarly  favored  we  shall  have  in  the  photographs  a  series 
of  successive  pictures  taken  at  intervals  of  time  sufficiently 
distant  to  reveal  any  progressive  changes  that  may  have  oc- 
curred in  the  corona  while  the  moon's  shadow  was  passing 
from  one  station  to  the  other.  I  anticipate  some  curious 
revelations  from  these  progressive  photographs,  that  may 
possibly  reconcile  the  wide  differences  in  the  descriptions 
that  competent  observers  have  given  of  the  corona  of  former 


94  SCIENCE  IN  SHORT  CHAPTERS. 

eclipses,  which  they  had  seen  at  stations  distant  from  each 
other. 

Barely  two  years  have  elapsed  since  I  suggested,  in  "The 
Fuel  of  the  Sun,"  that  the  great  solar  prominences  and  the 
corona  are  due  to  violent  explosions  of  the  dissociated  ele- 
ments of  water ;  that  the  prominences  are  the  gaseous 
flashes,  and  the  corona  the  ejected  scoria,  or  solidified 
metallic  matter  belched  forth  by  the  furious  cannonade 
continually  in  progress  over  the  greater  portion  of  the  solar 
surface. 

This  explanation  at  first  appeared  extravagant,  especially 
as  it  was  carried  so  far  as  to  suggest  that  not  merely  the 
corona,  but  the  zodiacal  light,  the  zone  of  meteors  which 
occasionally  drop  showers  of  solid  matter  upon  the  earth, 
and  even  the  "  pocket-planets"  or  asteroids  so  irregularly 
scattered  between  the  orbits  of  Mars  and  Jupiter,  consist  of 
solid  matter  thus  ejected  by  the  great  solar  eruptions. 
Even  up  to  the  spring  of  the  present  year,  when  Mr.  Lock- 
yer  and  other  leaders  of  the  last  year's  expeditions  reported 
their  imperfect  results,  and  compared  them  with  various 
theories,  this  one  was  not  thought  worthy  of  their  atten- 
tion. 

Since  that  time — during  the  past  six  or  eight  months — a 
change  has  taken  place  which  strikingly  illustrates  the  rapid 
progress  of  solar  discoveiy.  Observations  and  calculations 
of  the  force  and  velocity  of  particular  solar  eruptions  have 
been  made,  and  the  results  have  proved  that  they  are  amply 
sufficient  to  eject  solid  missiles  even  further  than  I  supposed 
them  to  be  carried. 

Mr.  Proctor,  basing  his  calculations  upon  the  observa- 
tions of  Respighi,  Zollner,  and  Professor  Young,  has  con- 
cluded that  it  is  even  possible  that  meteoric  matter  may  be 
ejected  far  beyond  the  limits  of  our  solar  system  into  the 
domain  of  the  gravitation  of  other  stars,  and  that  other  stars 
may  in  like  manner  bombard  the  sun. 

This  appears  rather  startling;  but,  as  I  have  already  said, 
the  imagination  of  the  poet  and  the  novelist  is  beggared  by 
the  facts  revealed  by  the  microscope,  so  I  may  now  repeat 
the  assertion,  and  state  it  still  more  strongly,  in  reference 
to  the  revelations  of  the  telescope  and  the  spectroscope. 


THE  SOLAR  ECLIPSE  OF  1871.  95 

As  a  sample  of  these,  I  take  the  observations  of  Profes- 
sor Young,  made  on  September  7th  last,  and  described 
fully  in  "  Nature"  on  October  19. 

He  first  observed  a  number  of  the  usual  flame-prominen- 
ces having  the  typical  form  which  has  been  compared  to  a 
"banyan  grove."  One  of  these  banyans  was  greater  than 
the  rest.  This  monarch  of  the  solar  flame-forest  measured 
fifty -four  thousand  miles  in  height,  and  its  outspreading 
measured  in  one  direction  about  one  hundred  thousand 
miles.  It  was  a  large  eruption-flame,  but  others  much 
larger  have  been  observed,  and  Professor  Young  would 
probably  have  merely  noted  it  among  the  rest,  had  not 
something  further  occurred.  He  was  called  away  for  twen- 
ty-five minutes,  and  when  he  returned  "the  whole  thing 
had  been  literally  blown  to  shreds  by  some  inconceivable 
uprush  from  beneath."  The  space  around  "  was  filled  with 
flying  debris — a  mass  ol  detached  vertical  fusiform  fila- 
ments, each  from  10  sec.  to  30  sec.  long  by  2  sec.  or  3  sec. 
wide,  brighter  and  closer  together  where  the  pillars  had 
formerly  stood,  and  rapidly  ascending."  Professor  Young 
goes  onto  say,  that  "When  I  first  looked,  some  of  them 
had  already  reached  a  height  of  100,000  miles,  and  while  I 
watched  they  rose,  with  a  motion  almost  perceptible  to  the 
eye,  until  in  ten  minutes  the  uppermost  were  200,000  miles 
above  the  solar  surface.  This  was  ascertained  by  careful 
measurement." 

Here,  then,  we  have  an  observed  velocity  of  10,000  miles 
per  minute,  and  this  is  the  gaseous  matter,  merely  the  flash 
of  the  gun  by  which  the  particles  of  solidified  solar  matter 
are  supposed  to  be  projected. 

The  reader  must  pause  and  reflect,  in  order  to  form  an 
adequate  conception  of  the  magnitudes  here  treated — 100,- 
000  miles  long  and  54,000  miles  high!  What  does  this 
mean?  Twelve  and  a  half  of  our  worlds  placed  side  by  side 
to  measure  the  length,  and  six  and  three  quarters,  piled 
upon  each  other,  to  measure  the  height!  A  few  hundred 
worlds  as  large  as  ours  would  be  required  to  fill  up  the 
whole  cubic  contents  of  this  flame-cloud.  The  spectroscope 
has  shown  that  these  prominences  are  incandescent  hydro- 
gen. Most  of  my  readers  have  probably  seen  a  soap-bubble 


96  SCIENCE  IN  SHORT  CHAPTERS. 

or  a  bladder  filled  with  the  separated  elements  of  water, 
and  then  exploded,  and  have  felt  the  ringing  in  their  ears 
that  has  followed  the  violent  detonation. 

Let  them  struggle  with  the  conception  of  such  a  bubble 
or  bladder  magnified  to  the  dimensions  of  only  one  such  a 
world  as  ours,  and  then  exploded;  let  them  strain  their 
power  of  imagination  even  to  the  splitting  point,  and  still 
they  must  fail  most  pitifully  to  picture  the  magnitude  of 
this  solar  explosion  observed  on  September  7th  last,  which 
flashed  out  to  a  magnitude  of  more  than  five  hundred 
worlds,  and  then  expanded  to  the  size  of  more  than  five 
thousand  worlds,  even  while  Professor  Young  was  watching 
it.  Professor  Young  concludes  his  description  by  stating 
that  "it  seerns  far  from  impossible  that  the  mysterious 
coronal  streamers,  if  they  turn  out  to  be  truly  solar,  as  now 
seems  likely,  may  find  their  origin  and  explanation  in  such 
events." 

This,  and  a  number  of  similar  admissions,  suggestions, 
and  conclusions  from  the  leading  astronomers,  indicate  that 
the  eruption  theory  of  the  corona  will  not  be  passed  over  in 
silence  by  the  observers  of  this  eclipse,  and  it  is  to  this  that 
I  have  referred  in  the  above  remarks  respecting  the  interest 
attaching  to  a  series  of  photographs  showing  successive 
states  of  this  outspreading  enigma. 

Father  Secchi's  spectroscopic  observations  on  the  un- 
eclipsed  sun  led  him  to  assert  the  existence  of  a  stratum  of 
glowing  metallic  vapors  immediately  below  the  envelope 
connected  with  the  hydrogen  of  the  eruptions.  This  is 
just  what  is  required  by  my  eruption  theory  to  supply  the 
solid  materials  of  the  ejections  forming  the  corona. 

Professor  Young's  announcement  of  the  reversal  of  the 
spectroscopic  lines  at  the  moment  when  the  stratum  was 
seen  independently  of  the  general  solar  glare,  startled  Mr. 
Lockyer  and  others  who  had  disputed  the  accuracy  of  the 
observations  of  the  great  Italian  observer,  as  it  confirmed 
them  so  completely.  Scepticism  still  prevailed,  and  Young's 
observation  was  questioned;  but  now  even  our  slender  tele- 
graphic communication  from  Colonel  Tenant  to  Dr.  Hug- 
gins  indicates  that  the  question  must  be  no  longer  contested. 
"Reversion  of  lines  entirely  confirmed  "is  a  message  so  im- 


THE  SOLAR  ECLIPSE  OF  1871.  97 

portant  that  if  the  expeditions  had  done  no  more  than  this, 
all  their  cost  in  money  and  scientific  labor  would  be  amply 
repaid  in  the  estimation  of  those  who  understand  the  value 
of  pure  truth. 

A  few  more  fragments  of  intelligence  respecting  the 
Eclipse  Expedition  have  reached  us,  the  last  Indian 
mail  having  started  just  after  the  eclipse  occurred.  They 
fully  confirm  the  first  telegraphic  announcement,  rather 
strengthening  than  otherwise  the  expectations  of  important 
results,  especially  in  reference  to  the  photographs  of  the* 
corona. 

I  have  read  in  the  Ceylon  newspapers  some  full  descrip- 
tions by  amateur  observers,  in  which  the  general  magnifi- 
cence of  the  phenomena  is  described.  From  these  it  is 
evident  that  the  corona  must  have  been  displayed  in  its 
full  grandeur  ;  but  as  the  writers  do  not  attempt  to  de- 
scribe those  features  which  have  at  the  present  moment  a 
special  scientific  interest,  I  shall  not  dwell  upon  them,  but 
await  the  publication  of  the  official  report  of  the  chief,  and 
of  the  more  important  collateral  observing  expeditions. 

The  unsophisticated  reader  may  say  "  Are  not  one  man's 
eyes  as  good  as  another's,  and  why  should  the  observations 
of  the  learned  men  of  the  expeditions  be  so  much  better 
than  those  of  any  other  clear-sighted  persons  ?  "  This  is  a 
perfectly  fair  question,  and  admits  of  a  ready  answer.  All 
that  can  be  known  by  mere  unprepared  naked-eye  observa- 
tion is  tolerably  well  known  already  ;  the  questions  which 
await  solution  can  only  be  answered  by  putting  the  sun  to 
torture  by  means  of  instruments  specially  devised  for  that 
purpose ;  and  by  a  skillful  organization,  and  division  of 
labor  among  the  observers. 

There  is  so  much  to  be  seen  during  the  few  seconds  of 
total  obscuration  that  no  one  human  being,  however  well 
trained  in  the  art  of  observing,  could  possibly  see  all. 
Therefore  it  is  necessary  to  pre-arrange  each  observer's 
part,  to  have  careful  rehearsals  of  what  is  to  be  done  by 
eacli  during  the  precious  seconds;  and  each  man  must 
exercise  a  vast  amount  of  self-control  in  order  to  confine 
his  attention  to  his  own  particular  bit  of  observation,  while 


98  SCIENCE  IN  SHORT  CHAPTERS. 

he  is  surrounded  with  such  marvellous  phenomena  as  a  total 
eclipse  presents. 

The  grandeur  of  the  gloomy  landscape,  the  sudden 
starting  out  of  the  greater  stars,  the  seeming  falling  of 
the  vault  of  heaven,  the  silence  of  the  animal  world,  the 
closing  of  the  flowers,  and  all  that  the  ordinary  observer 
would^  regard  with  so  much  awe  and  wondering  delight, 
must  be  sacrificed  by  the  philosopher,  whose  business  is 
to  confine  his  gaze  to  a  narrow  slit  between  two  strips  of 
.metal,  and  to  watch  nothing  else  but  the  exact  position 
and  appearance  of  a  few  bright  or  dark  lines  across  what 
appears  but  a  strip  of  colored  riband.  He  must  resist  the 
temptation  to  look  aside  and  around  with  the  stubbornness 
of  self-denial  of.  another  St.  Antonio.  Besides  this,  he 
must  thoroughly  understand  exactly  what  to  look  for,  and 
how  to  find  it.  By  combining  the  results  of  his  observa- 
tions with  those  of  the  others,  who  in  like  manner  have 
undertaken  to  work  with  another  instrument,  or  upon 
another  part  of  the  phenomena,  we  get  a  scientific  result 
comparable  to  that  which  in  a  manufactory  we  obtain  by 
the  division  of  labor  of  many  skilled  workmen,  each  doing 
only  that  which  by  his  training  he  has  learned  to  do  the 
best  and  the  most  expeditiously. 

FURTHER  DETAILS  BY  POST. 

Although  the  formal  official  reports  of  the  Eclipse  Ex- 
pedition are  not  yet  published,  and  may  not  be  for  some 
weeks  or  months,  we  are  able  from  the  letters  of  Lockyer, 
Jannsen,  Respighi,  Maclear,  etc.,  to  form  some  idea  of  the 
general  results.  We  may  already  regard  two  or  three  im- 
portant questions  as  fairly  answered.  The  reversal  of  the 
dark  solar  lines  of  the  spectrum  which  was  first  announced 
by  the  great  Eoman  observer,  Father  Secchi,  and  seen  by 
him  without  an  eclipse,  may  now  be  considered  as  estab- 
lished. It  is  true  that  all  the  observers  of  1871  did  not 
witness  this.  Some  were  doubtful,  but  others  observed 
it  positively  and  distinctly. 

In  such  a  case  negative  results  do  not  refute  the  positive 
observations  of  qualified  men,  especially  when  several  of 


THE  SOLAR  ECLIPSE  OF  1871.  99 

such  observations  have  been  made  independently ;  the 
phenomenon  is  but  instantaneous,  a  mere  flash  of  bright 
stripes  in  place  of  dark  lines  across  the  colored  riband  of 
the  spectroscope,  which  happens  just  at  the  moment  be- 
fore and  after  totality,  and  is  presented  only  when  the 
instrument  is  accurately  directed  to  the  delicate  curved 
vanishing  thread  of  light  which  is  the  last  visible  frag- 
ment of  the  solar  outline,  and  that  which  makes  the  first 
flash  of  his  re-appearance. 

A  little  explanation  is  necessary  to  render  the  signifi- 
cance of  this  "reversal"  intelligible  to  those  who  have 
not  specially  studied  the  subject. 

1st.  When  the  spectroscope  is  directed  to  a  luminous 
solid  a  simple  rainbow-band  or  "  continpus  spectrum"  is 
seen.  When,  on  the  other  hand,  the  object  is  a  luminous 
gas  or  vapor  of  moderate  density,  the  spectrum  is  not  a 
continuous  band  with  its  colors  actually  blending ;  it  con- 
sists only  of  certain  luminous  stripes  with  blank  spaces 
between  them,  each  particular  gas  or  vapor  showing  its  own 
particular  set  of  stripes  of  certain  colors,  and  always  ap- 
pearing at  exactly  the  same  place,  so  invariably  and  cer- 
tainly, that,  by  means  of  such  luminous  stripes,  the  compo- 
sition of  the  gas  or  vapor  may  be  determined.  If,  however, 
the  gas  be  much  compressed,  the  stripes  widen  as  the  con- 
densation proceeds  ;  they  may  even  spread  out  sufficiently 
to  meet  and  form  a  continuous  spectrum  like  that  from  a 
solid.  Liquids  also  produce  continuous  spectra. 

3d.  When  a  luminous  solid  or  liquid,  or  very  dense  gas, 
capable  of  producing  a  continuous  spectrum,  is  viewed 
through  an  intervening  body  of  other  gas  or  vapor  of 
moderate  or  small  density,  fine  dark  lines  cross  the  spec- 
trum in  precisely  the  same  places  as  the  bright  stripes 
would  appear  if  this  intervening  gas  or  vapor  were  lumi- 
nous and  seen  by  itself. 

When  the  spectroscope  is  directed  to  the  face  of  the  sun 
under  ordinary  circumstances,  it  presents  a  brilliant  con- 
tinuous spectrum,  striped  with  a  multitude  of  the  dark 
lines.  From  this  it  has  been  inferred  that  the  luminous 
face  of  the  sun  is  that  of  an  incandescent  solid  or  liquid, 
and  that  it  is  surrounded  by  the  gases  and  vapors  whose 


100  SCIENOE  IN  SHORT  CHAPTERS. 

bright  stripes,  when  artificially  produced,  occupy  precisely 
the  same  places  as  the  dark  lines  of  the  solar  spectrum. 
This  was  the  theory  of  Kirchoff  and  others  in  the  early 
days  of  spectrum  analysis,  when  it  was  only  known  that 
solids  and  liquids  were  capable  of  producing  a  continuous 
spectrum.  The  important  discovery  that  gases  and  vapors, 
if  sufficiently  condensed,  will  also  produce  a  continuous 
spectrum,  opened  another  speculation,  far  more  consistent 
with  the  other  known  facts  concerning  the  constitution  of 
the  sun,  viz.,  that  the  sun  maybe  a  great  gaseous  orb,  blaz- 
ing at  its  surface  and  gradually  increasing  in  density  from 
the  surface  towards  the  centre. 

According  to  this,  the  metals  sodium,  calcium,  barium, 
magnesium,  iron,  chromium,  nickel,  copper,  zinc,  stron- 
tium, cobalt,  manganese,  aluminium,  and  titanium,  whose 
vapors,  with  those  of  some  few  other  substances,  give  the 
dark  lines  that  cross  the  solar  spectrum,  should  exist  neither 
as  solids  nor  liquids  on  the  solar  surface,  but  as  blazing 
gases.  But  such  blazing  gases,  according  to  what  I  have 
stated  above,  should  give  us  bright  stripes  instead  of  dark 
lines.  Why,  then,  are  not  such  bright  stripes  seen  under 
ordinary  circumstances? 

This  is  easily  answered.  These  blazing  gases  must,  as 
we  proceed  from  the  surface  of  the  sun  downwards,  become 
so  condensed  by  the  pressure  of  their  own  superincumbent 
strata,  as  to  produce  a  continuous  spectrum  of  great  bril- 
liancy. With  such  a  background  the  bright  stripes  would 
be  confounded  and  lost  to  sight.  Besides  this,  the  outer 
film  of  cooler  vapor  through  which  our  vision  must  neces- 
sarily penetrate  before  reaching  the  luminous  solar  surface, 
will  produce  the  dark  lines  exactly  where  the  bright  stripes 
should  be,  and  thus  effectually  obliterate  them  ;  or,  in  other 
words,  the  intervening  non-luminous  vapors  are  opaque  to 
the  particular  rays  of  light  which  the  bright  vapors  of  the 
same  substance  emits. 

Therefore,  according  to  this  theory,  if  we  could  sweep 
away  these  outside  darkening  vapors,  and  screen  off  the  in- 
ner layers  of  denser  blazing  matter  which  produces  the 
continuous  background,  we  should  have  a  spectrum  dis- 


THE  SOLAR  ECLIPSE  OF  1871.  101 

playing  a  multitude  of  bright  stripes  exactly  where  the 
black  lines  of  the  ordinary  solar  spectrum  appear. 

Secchi  announced  that  these  bright  lines  were  to  be  seen 
under  favorable  circumstances,  when,  by  skillful  manage- 
ment, the  rays  from  the  edge  of  the  sun  were  so  caught  by 
the  slit  of  the  spectroscope  as  to  exhibit  only  the  spectrum 
of  the  superficial  layer  of  the  sun's  bright  surface.  This 
was  disputed  at  the  time  by  Mr.  Lockyer,  who,  I  suspect, 
omitted  to  consider  the  atmospheric  difficulties  under  which 
English  astronomers  work,  and  the  fact  that  the  atmos- 
phere of  Italy  is  exceptionally  favorable  for  delicate  as- 
tronomical observation. 

If  he  had  fairly  considered  this  I  think  he  would  agree 
with  me  in  concluding  that  an  observation  of  this  kind, 
avowedly  made  with  great  difficulty  and  questionable  dis- 
tinctness by  so  skillful  a  spectroscopic  observer  as  Father 
Secchi,  could  not  possibly  be  seen  by  any  human  eyes 
through  a  London  atmosphere. 

Subsequently  Professor  Young  startled  the  astronomical 
world  by  the  announcement  that,  at  the  moment  when  the 
thinnest  perceptible  thread  of  the  sun's  edge  was  alone  dis- 
played during  the  eclipse  which  he  observed,  the  whole  of 
the  dark  lines  of  the  solar  spectrum  flashed  out  as  bright 
stripes  in  a  most  unmistakable  manner.  This  observation 
is  now  fully  confirmed.  The  first  telegrams  from  Mr.  Pog- 
son,  the  Government  astronomer  of  Madras,  and  from  Col- 
onel Tennant,  both  announce  this  most  positively,  Colonel 
Tennant's  words  being,  "  the  reversion  of  the  lines  fully 
confirmed."  A  similar  result  was  obtained  by  some,  but 
not  by  all,  of  the  Ceylon  observers. 

To  understand  this  clearly,  we  must  consider  the  fact 
that  what  appears  to  us  as  the  outline  of  aflat  disc  is  really 
that  part  of  the  sun  which  we  see  by  looking  horizontally 
athwart  his  rotundity,  just  as  we  look  at  the  ocean  surface 
of  our  own  earth  when  we  stand  upon  the  shore  and  see  its 
horizon  outline.  When  the  moon  obscures  all  but  the  last 
film  of  this  solar  edge,  we  "See  only  the  surface  of  the  sup- 
posed gaseous  orb,  just  that  portion  of  the  blazing  gases 
which  are  not  greatly  compressed  by  those  above  them,  and 
which  accordingly  should,  if  they  consist  of  the  vapors  or 


102  SCIENCE  IN  SHORT  CHAPTERS. 

the  gases  above  named,  display  a  bright-striped  spectrum, 
provided  the  intervening  non-luminous  vapors  of  the  same 
metals  are  not  sufficiently  abundant  to  obscure  them — at 
this  particular  moment,  when  only  the  absolute  horizon- 
line  is  seen,  and  the  body  of  the  moon  cuts  off  all  the  inter- 
vening solar  surface,  and  the  lower  or  denser  portion  of 
the  intervening  super-solar  vapors,  though,  of  course,  these 
are  not  so  entirely  cut  off  as  the  continuous  background. 

The  reversion  of  the  dark  lines  therefore  reveals  to  us  the 
stupendous  fact  that  the  surface  of  the  mighty  sun,  which 
is  as  big  as  a  million  and  a  quarter  of  our  worlds,  consists 
of  a  flaming  ocean  of  hydrogen  and  of  the  metals  above- 
named  in  a  gaseous  condition,  similar  to  that  of  the  hydro- 
gen itself. 

This  fact,  coupled  with  the  other  revelations  of  the  spec- 
troscope, which,  without  the  help  of  an  eclipse,  reveals  the 
surface  outline  of  the  sun,  the  "sierra"  and  the  "promi- 
nences" tell  us  that  this  flaming  ocean  is  in  a  state  of  per- 
petual tempest,  heaving  up  its  billows  and  flame- Alps 
hundreds  and  thousands  of  miles  in  height,  and  belching 
forth  above  all  these  still  taller  pillars  of  fire  that  even 
reach  an  elevation  of  more  than  a  hundred  thousand  miles, 
and  then  burst  out  into  mighty  clouds  of  flame  and  vapor, 
bigger  than  five  hundred  worlds. 

What  does  the  last  eclipse  teach  us  in  reference  to  the 
corona?  Firstly  and  clearly,  that  Lockyer's  explanation 
which  attributed  it  to  an  illumination  of  the  upper  regions 
of  the  earth's  atmosphere  must  be  now  for  ever  abandoned. 
This  theory  has  died  hard,  but,  in  spite  of  Mr.  Lockyer's 
proclamation  of  "victory  all  along  the  line,"  it  is  now  past 
galvanizing.  There  can  be  no  further  hesitation  in  pro- 
nouncing that  the  corona  actually  belongs  to  the  sun  itself, 
that  it  is  a  marvelous  solar  appendage  extending  from  the 
sun  in  all  directions,  but  by  no  means  regularly. 

The  immensity  of  this  appendage  will  be  best  understood 
by  the  fact  that  the  space  included  within  the  outer  limits 
of  the  visible  corona  is  at  least*twenty  times  as  great  as  the 
bulk  of  the  sun  itself,  that  above  twenty-five  millions  of 
our  worlds  would  be  required  to  fill  it. 

Jannsen  says:  "I  believe  the  question  whether  the  co- 


THE  SOLAR  ECLIPSE  OF  1871.  103 

rona  is  due  to  the  terrestrial  atmosphere  is  settled,  and  we 
haye  before  us  the  prospect  of  the  study  of  the  extra-solar 
regions,  which  will  be  very  interesting  and  fertile." 

The  spectroscope,  the  polariscope,  and  ordinary  vision 
all  concur  in  supporting  the  explanation  that  the  corona  is 
composed  of  solid  particles  and  gaseous  matter  intermin- 
gled. It  fulfils  exactly  all  the  requirements  of  the  hypothe- 
sis which  attributes  it  to  the  same  materials  as  those  which 
in  a  gaseous  state  cause  the  reversion  of  the  dark  lines 
above  described,  but  which  have  been  ejected  with  the  great 
eruptions  forming  the  solar  prominences,  and  have  become 
condensed  into  glowing  metallic  hailstones  as  their  distance 
from  the  central  heat  has  increased.  These  must  neces- 
sarily be  accompanied  by  the  vapors  of  the  more  volatile 
materials,  and  should  give  out  some  of  the  lighter  gases, 
such  as  hydrogen,  which,  under  greater  pressure,  would  be 
occluded  within  them,  just  as  the  hydrogen  gas  occluded 
within  the  substance  of  the  Lenarto  meteor  (a  mass  of  iron 
which  fell  from  the  skv  upon  the  earth)  was  extracted  by 
the  late  Master  of  the  Mint  by  means  of  his  mercurial  air- 
pump. 

The  rifts  or  gaps  between  the  radial  streamers,  which 
have  been  so  often  described  and  figured,  but  were  regarded 
by  some  as  optical  illusions,  are  now  established  as  unques- 
tionable facts.  Mr.  Lockyer,  the  last  to  be  convinced,  is 
now  compelled  to  admit  this,  which  overthrows  the  suppo- 
sition that  this  solar  appendage  is  a  luminous  solar  atmos- 
phere of  any  kind.  If  it  were  gaseous  or  true  vapor,  it 
must  obey  the  law  of  gaseous  diffusion,  and  could  not  pre- 
sent the  phenomena  of  bright  radial  streamers,  with  dark 
spaces  between  them,  unless  it  were  in  the  course  of  very 
rapid  radial  motion  either  to  or  from  the  sun. 

The  photographs  have  not  yet  been  published.  When 
they  have  all  arrived,  and  can  be  compared,  we  shall  learn 
something  that  I  anticipate  will  be  extremely  interesting 
respecting  the  changes  of  the  corona,  as  they  have  been 
taken  at  the  different  stations  at  different  times.  I  alluded 
to  this  subject  before,  when  it  was  only  a  matter  of  possi- 
bility that  such  a  succession  of  pictures  might  have  been 
taken.  We  now  have  the  assurance  that  such  pictures 


104  SCIENCE  IN  SHORT  CHAPTERS. 

have  been  obtained.  There  can  be  no  question  about  opti- 
cal illusion  in  these;  they  are  original  affidavits  made  by 
the  corona  itself,  signed,  sealed,  and  delivered  as  its  own 
act  and  deed. 


METEORIC  ASTRONOMY. 

THI  number  of  the  Quarterly  Journal  of  Science  for 
May,  1872,  contains  some  articles  of  considerable  interest. 
The  first  is  by  the  indefatigable  Mr.  Proctor,  on  "  Meteoric 
Astronomy,"  in  which  he  embodies  a  clear  and  popular 
summary  of  the  researches  which  have  earned  for  Sign  or 
Schiaparelli  this  year's  gold  medal  of  the  Astronomical 
Society.  Like  all  who  venture  upon  a  broad,  bold  effort 
of  scientific  thought,  extending  at  all  into  the  regions  of 
philosophical  theory,  Schiaparelli  has  had  to  wait  for  recog- 
nition. A  simple  and  merely  mechanical  observation  of  a 
bare  fact,  barely  and  mechanically  recorded  without  the 
exercise  of  any  other  of  the  intellectual  faculties  than  the 
external  senses  and  observing  powers,  is  at  once  received 
and  duly  honored  by  the  scientific  world;  but  any  higher 
effort  is  received  at  first  indifferently,  or  sceptically,  and  is 
only  accepted  after  a  period  of  probation,  directly  propor- 
tionate to  its  philosophical  magnitude  and  importance,  and 
inversely  proportionate  to  the  scientific  status  of  the  daring 
theorist. 

At  first  sight  this  appears  unjust,  it  looks  like  honoring 
the  laborers  who  merely  make  the  bricks,  and  despising  the 
architect  who  constructs  the  edifice  of  philosophy  from  the 
materials  they  provide.  Many  a  disappointed  dreamer, 
finding  that  his  theory  of  the  universe  has  not  been  ac- 
cepted, and  that  the  expected  honors  have  not  been  show- 
ered upon  him,  has  violently  attacked  the  whole  scientific 
community  as  a  contemptible  gang  of  low-minded  mechani- 
cal plodders,  void  of  imagination,  blind  to  all  poetic  aspira- 
tions, and  incapable  of  any  grand  and  comprehensive  flight 
of  intellect. 


METEORIC  ASTRONOMY.  105 

Had  these  impulsive  gentlemen  been  previously  subjected 
to  the  strict  discipline  of  inductive  scientific  training,  their 
position  and  opinions  would  have  been  very  different. 
Their  great  theories  would  either  have  had  no  existence,  or 
have  been  much  smaller,  and  they  would  understand  that 
philosophic  caution  is  one  of  the  characteristic  results  of 
scientific  training. 

Simple  facts,  which  can  be  immediately  proved  by  simple 
experiments  and  simple  observations,  are  at  once  accepted, 
and  their  discoverers  duly  honored,  without  any  hesitation 
or  delay,  but  the  grander  efforts  of  generalization  require 
careful  thought  and  laborious  scrutiny  for  their  verifica- 
tion, and  therefore  the  acknowledgment  of  their  merits  is 
necessarily  delayed;  but  when  it  does  arrive  full  justice  is 
usually  done. 

Thus  Grove's  "  Correlation  of  the  Physical  Forces,"  the 
greatest  philosophical  work  on  purely  physical  science  of 
this  generation,  was  commenced  in  1842,  when  its  author 
occupied  but  a  humble  position  at  the  London  Institution. 
The  book  was  but  little  noticed  for  many  years,  and,  had 
Mr.  Grove  (now  Sir  William  Grove)  not  been  duly  educated 
by  the  discipline  above  referred  to,  he  might  have  become 
a  noisy  cantankerous  martyr,  one  of  those  "ill-used  men" 
who  have  been  made  familiar  to  so  many  audiences  by  Mr. 
George  Dawson. 

Instead  of  this,  he  patiently  waited,  and,  as  we  have  lately 
seen,  the  well-deserved  honors  have  now  been  liberally 
awarded. 

In  a  very  few  years  hence  we  shall  be  able  to  say  the  same 
of  the  once  diabolical  Darwin,  and  eight  or  nine  other  theo- 
rists,  who  must  all  be  content  to  take  their  trial  and 
patiently  await  the  verdict;  the  time  of  waiting  being  of 
necessity  proportionate  to  the  magnitude  of  the  issue. 

The  theories  of  Schiaparelli,  which,  as  Mr.  Proctor  says, 
"after  the  usual  term  of  doubt  have  so  recently  received 
the  sanction  of  the  highest  astronomical  tribunal  of  Great 
Britain,"  are  not  of  so  purely  speculative  a  character  as  to 
demand  a  very  long  "term  of  doubt."  They  are  directly 
based  on  observations  and  mathematical  calculations  which 
bring  them  under  the  domain  of  the  recognized  logic  of 


106  SCIENCE  IN  SHOUT  CHAPTERS. 

mathematical  probability.  Those  who  are  specially  inter- 
ested in  the  modern  progress  of  astronomy  should  read 
tliis  article  in  the  Quarterly  Journal  of  Science,  which  is 
illustrated  with  the  diagrams  necessary  for  the  comprehen- 
sion of  the  researches  and  reasoning  of  Schiaparelli  and 
others  who  hare  worked  on  the  same  ground. 

I  can  only  state  the  general  results,  which  are  that  the 
meteors  which  we  see  every  year,  more  or  less  abundantly, 
on  the  nights  of  the  10th  and  llth  of  August,  and  which 
always  appear  to  come  from  the  same  point  in  the  heavens, 
are  then  and  thus  visible  because  they  form  part  of  an 
eccentric  elliptical  zone  of  meteoric  bodies  which  girdle  the 
domain  of  the  sun;  and  that  our  earth,  in  the  course  of  its 
annual  journey  around  the  sun,  crosses  and  plunges  more 
or  less  deeply  into  this  ellipse  of  small  attendant  bodies, 
which  are  supposed  to  be  moving  in  regulur  orbits  around 
the  sun. 

Schiaparelli  has  compared  the  position,  the  direction, 
and  the  velocity  of  motion  of  the  August  meteors  with  the 
orbit  of  the  great  comet  of  1862,  and  infers  that  there  is  a 
close  connection  between  them,  so  close  that  the  meteors 
may  be  regarded  as  a  sort  of  trail  which  the  comet  has  left 
behind.  He  does  not  exactly  say  that  they  are  detached 
vertebrae  of  the  comet's  tail,  but  suggests  the  possibility  of 
their  original  connection  with  its  head. 

Similar  observations  have  been  made  upon  the  Novem- 
ber meteoric  showers,  which  by  similar  reasoning,  are  as- 
sociated with  another  comet;  and  further  yet,  it  is  assumed 
upon  analogy  that  other  recognized  meteor  systems,  amount- 
ing to  nearly  two  hundred  in  number,  are  in  like  manner 
associated  with  other  comets. 

If  these  theories  are  sound,  our  diagrams  and  mental 
pictures  of  the  solar  system  must  be  materially  modified. 
Besides  the  central  sun,  the  eight  planets  and  the  asteroids 
moving  in  their  nearly  circular  orbits,  and  some  eccentric 
comets  traveling  in  long  ellipses,  we  must  add  a  countless 
multitude  of  small  bodies  clustered  in  elliptical  rings,  all 
traveling  together  in  the  path  marked  by  their  containing 
girdle,  and  following  the  lead  of  a  streaming  vaporous  mon- 
ster, their  parent  comet. 


METEORIC  ASTRONOMY.  107 

We  must  count  such  comets,  and  such  rings  filled  with 
attendant  fragments,  not  merely  by  tens  or  hundreds,  but 
by  thousands  and  tens  of  thousands,  even  by  millions;  the 
path  of  the  earth  being  but  a  thread  in  space,  and  yet  a 
hundred  or  two  are  strung  upon  it. 

In  this  article  Mr.  Proctor  seems  strongly  disposed  to 
return  to  the  theory  which  attributes  solar  heat  and  light 
to  a  bombardment  of  meteors  from  without,  and  the  solar 
corona  and  zodiacal  light  as  visible  presentments  of  these 
meteors.  Still,  however,  he  clings  to  the  more  recent  ex- 
planation which  regards  the  corona,  the  zodiacal  light,  and 
the  meteors  as  matter  ejected  from  the  sun  by  the  same 
forces  as  those  producing  the  solar  prominences.  For  my 
own  part  I  shall  not  be  at  all  surprised  if  we  find  that,  ere 
long,  these  two  apparently  conflicting  hypotheses  are  fully 
reconciled. 

The  progress  of  solar  discovery  has  been  so  great  since 
January,  1870,  when  my  eject! on  theory  was  published,  that 
I  may  now  carry  it  out  much  further  than  I  then  dared,  or 
was  justified  in  daring  to  venture.  Actual  measurement 
of  the  projectile  forces  displayed  in  some  of  the  larger 
prominences  renders  it  not  merely  possible,  but  even  very 
probable,  that  some  of  the  exceptionally  great  eruptive 
efforts  of  the  sun  may  be  sufficiently  powerful  to  eject  solar 
material  beyond  the  reclaiming  reach  of  his  own  gravitating 
power. 

In  such  a  case  the  banished  matter  must  go  on  wander- 
ing through  the  boundless  profundity  of  space  until  it 
reaches  the  domain  of  some  other  sun,  which  will  clutch 
the  fragment  with  its  gravitating  energies,  and  turn  its 
straight  and  ever  onward  course  into  the  curved  orbit. 
Thus  the  truant  morsel  from  our  sun  will  become  the  sub- 
ject of  another  sun — a  portion  of  another  solar  system. 

What  one  sun  may  do,  another  and  every  other  may  do 
likewise,  and,  if  so,  there  must  be  a  mutual  bombardment, 
a  ceaseless  interchange  of  matter  between  the  countless 
suns  of  the  universe.  This  is  a  startling  view  of  our  cosmi- 
cal  relations,  but  we  arc  driving  rapidly  towards  a  general 
recognition  of  it. 

The  November  star  showers  have  perpetrated  some  irreg- 


108  SCIENCE  IN  SHORT  CHAPTERS. 

ularities  this  year.  They  have  been  very  unpunctual,  and 
have  not  come  from  their  right  place.  We  have  heard 
something  from  Italy,  but  not  the  tidings  of  the  Leonides 
that  were  expected.  Instead  of  the  great  display  of  the 
month  occurring  on  the  13th  and  14th,  it  was  seen  on  the 
27th.  We  have  accounts  from  different  parts  of  England, 
Ireland,  Scotland,  and  Wales,  also  from  Italy,  Greece, 
Egypt,  etc. 

Mr.  Slinto,  in  a  letter  to  the  Times,  estimates  the  num- 
ber seen  at  Suez  as  reaching  at  least  30,000,  while  in  Italy 
and  Athens  about  200  per  minute  were  observed.  They 
were  not,  however,  the  Leonides,  that  is,  they  did  not  radi- 
ate from  a  point  in  the  constellation  Leo,  but  from  the  re- 
gion of  Andromeda.  Therefore  they  were  distinct  from 
that  system  of  small  wanderers  usually  designated  the 
"November  meteors,"  were  not  connected  with  Tempel's 
comet  (comet  1,  1866),  but  belong  to  quite  another  set. 

The  question  now  discussed  by  astronomers  is  whether 
they  are  connected  with  any  other  comet,  and,  if  so,  with 
which  comet? 

In  the  "Monthly  Notices"  of  the  Royal  Astronomical 
Society,  published  October  24th  last,  is  a  very  interesting 
paper  by  Professor  Herschel,  on  "Observations  of  Meteor 
Showers,"  supposed  to  be  connected  with  "  Biela's  comet," 
in  which  he  recommends  that  "  a  watch  should  be  kept 
during  the  last  week  in  November  and  the  first  week  in 
December," in  order  to  verify  "the  ingenious  suggestions 
of  Dr.  Weiss,"  which,  popularly  stated,  amount  to  this, 
viz.,  that  a  meteoric  cloud  is  revolving  in  the  same  orbit  as 
Biela's  comet,  and  that  in  1772  the  earth  dashed  through 
this  meteoric  orbit  on  December  10th.  In  1826  it  did  the 
same,  on  December  4th;  in  1852  the  earth  passed  through 
the  node  on  November  28th,  and  there  are  reasons  for  ex- 
pecting a  repetition  at  about  the  same  date  in  1872. 

The  magnificent  display  of  the  27th  has  afforded  an  im- 
portant verification  of  these  anticipations,  which  become 
especially  interesting  in  connection  with  the  curious  his- 
tory of  Biela's  comet,  which  receives  its  name  from  M. 
Biela,  of  Josephstadt,  Avho  observed  it  in  1826,  calculated 
its  orbit,  and  considered  it  identical  with  the  comets  of 


METEORIC  ASTRONOMY.  109 

1772,  1805,  etc.  It  travels  in  a  long  eccentric  ellipse,  and 
completes  its  orbit  in  2410  days — about  6f  years.  It  ap- 
peared again,  as  predicted,  in  1832  and  1846. 

Its  orbit  very  nearly  intersects  that  of  the  earth,  and 
thus  affords  a  "remote  possibility  of  that  sort  of  collision 
which  has  excited  so  much  terror  in  the  minds  of  many 
people,  but  which  an  enthusiastic  astronomer  of  the  present 
generation  would  anticipate  with  something  like  the  sensa- 
tional interest  which  stirs  the  soul  of  a  London  street-boy 
when  he  is  madly  struggling  to  keep  pace  with  a  fire- 
engine. 

The  calculations  for  1832  showed  that  this  comet  should 
cross  the  earth's  orbit  a  little  before  the  time  of  the  earth's 
arrival  at  the  same  place;  but  as  such  a  comet,  traveling 
in  such  an  orbit,  is  liable  to  possible  retardations,  the  cal- 
culations could  only  be  approximately  accurate,  and  thus 
the  sensational  astronomer  was  not  altogether  without  hope. 
This  time,  however,  he  was  disappointed  ;  the  comet  was 
punctual,  and  crossed  the  critical  node  about  a  month  be- 
fore the  earth  reached  it. 

As  though  to  compensate  for  this  disappointment,  the 
comet  at  its  next  appearance  exhibited  some  entirely  new 
phenomena.  It  split  itself  into  two  comets,  in  such  a  man- 
ner that  the  performance  was  visible  to  the  telescopic  ob- 
server. Both  of  these  comets  had  nuclei  and  short  tails, 
and  they  alternately  varied  in  brightness,  sometimes  one, 
then  the  other,  having  the  advantage.  They  traveled  on 
at  a  distance  of  about  156,000  miles  from  each  other,  with 
parallel  tails,  and  with  a  sort  of  friendly  communication 
in  the  form  of  a  faint  arc  of  light,  wh'ich  extended  as  a 
kind  of  bridge,  from  one  to  the  other.  Besides  this,  the 
one  which  was  first  the  brighter,  then  the  fainter,  and 
finally  the  brighter  again,  threw  out  two  additional  tails, 
one  of  which  extended  lovingly  towards  its  companion. 

The  time  of  return  in  1852  was  of  course  anxiously  ex- 
pected by  astronomers,  and  careful  watch  was  kept  for  the 
wanderers.  They  came  again  at  the  calculated  time,  still 
separated  as  before. 

They  were  again  due  in  1859,  in  1866,  and,  finally,  at 
about  the  end  of  last  November,  or  the  beginning  of  the 


110  SCIENCE  IN  SHORT  CHAPTERS. 

present  month.  Though  eagerly  looked  for  by  astrono- 
mers in  all  parts  of  the  civilized  world,  they  have  been 
seen  no  more  since  1852. 

What,  then,  has  become  of  them?  Have  they  further 
subdivided?  Have  they  crumbled  into  meteoric  dust? 
Have  they  blazed  or  boiled  into  thin  air?  or  have  they 
been  dragged  by  some  interfering  gravitation  into  another 
orbit?  The  last  supposition  is  the  most  improbable,  as 
none  of  the  visible  inhabitants  of  space  have  come  near 
enough  to  disturb  them. 

The  possibility  of  a  dissolution  into  smaller  fragments  is 
suggested  by  the  fact  that,  instead  of  the  original  single 
comet,  or  the  two  fragments,  meteoric  showers  have  fallen 
towards  the  earth  at  the  time  when  it  has  crossed  the  orbit 
of  the  original  comet,  and  these  showers  have  radiated  from 
that  part  of  the  heavens  in  which  the  comet  should  have 
appeared.  Such  was  the  case  with  the  magnificent  display 
of  November  27th,  and  astronomers  are  inclining  more  and 
more  to  the  idea  that  comets  and  meteors  have  a  common 
origin — the  meteors  are  little  comets,  or  comets  are  big 
meteors. 

In  the  latest  of  the  "Monthly  Notices,"  of  the  Eoyal 
Astronomical  Society,  published  last  week,  is  a  paper  by 
Mr.  Proctor,  in  which  he  expands  the  theory  expounded 
three  years  ago  by  an  author  whom  your  correspondent's 
modesty  prevents  him  from  naming,  viz.,  that  the  larger 
planets — Jupiter,  Saturn,  Uranus,  and  Neptune — are 
minor  suns,  ejecting  meteoric  matter  from  them  by  the  op- 
eration of  forces  similar  to  those  producing  the  solar  prom- 
incences. 

Mr.  Proctor  subjects  this  bold  hypothesis  to  mathematical 
examination,  and  finds  that  the  orbit  of  TempePs  comet 
and  its  companion  meteors  correspond  to  that  which  would 
result  from  such  an  eruption  occurring  on  the  planet 
Uranus.  An  eruptive  force  effecting  a  velocity  of  about 
thirteen  miles  per  second,  which  is  vastly  smaller  than  the 
actually  measured  velocity  of  the  matter  of  the  solar  erup- 
tions, would  be  sufficient  to  thrust  such  meteoric  or  come- 
tary  matter  beyond  the  reclaiming  reach  of  the  gravitation 
of  Uranus,  and  hand  it  over  to  the  sun,  to  make  just  such 


METEORIC  ASTRONOMY.  Ill 

an  orbit  as  that  of  Tempel's  comet  and  the  Leonides  me- 
teors. 

He  shows  that  other  comets  and  meteoric  zones  are  sim- 
ilarly allied  to  other  planets,  and  thus  it  may  be  that  the 
falling  stars  and  comets  are  fragments  of  Jupiter,  Saturn, 
Uranus,  or  Neptune.  Verily,  if  an  astronomer  of  the  last 
generation  were  to  start  up  among  us  now,  he  would  be 
astounded  at  modern  presumption. 

The  star  shower  of  November  27th,  and  its  connection 
with  Biela's  broken  and  lost  comet,  referred  to  in  my  last 
letter,  are  still  subjects  of  research  and  speculation.  On 
November  30th  Professor  Klinkerfues  sent  to  Mr.Pogson,  of 
the  Madras  Observatory,  the  following  startling  telegram: 
"  Biela  touched  earth  on  27th.  Search  near  Theta  Cen- 
tauri." 

Mr.  Pogson  searched  accordingly  from  comet-rise  to 
sunrise  on  the  two  following  mornings,  but  in  vain ;  for 
even  in  India  they  have  had  cloudy  weather  of  late.  On 
the  third  day,  however,  he  had  "better  luck,"  saw  some- 
thing like  a  comet  through  an  opening  between  clouds,  and 
on  the  following  days  was  enabled  to  deliberately  verify 
this  observation  and  determine  the  position  and  some 
elements  of  the  motion  of  the  comet,  which  displayed  a 
bright  nucleus,  and  faint  but  distinct  tail. 

This  discovery  is  rather  remarkable  in  connection  with 
the  theoretical  anticipation  of  Professor  Klinkerfues;  but 
the  conclusion  directly  suggested  is  by  no  means  admitted 
by  astronomers.  Some,  have  supposed  that  it  is  not  the 
primary  Biela,  but  the  secondary  comet,  or  offshoot,  which 
grazed  the  earth,  and  was  seen  by  Mr.  Pogson;  others  that 
it  was  neither  the  body,  the  envelope,  nor  the  tail  of  either 
of  the  comets  which  formed  the  star  shower,  but  that  the 
meteors  of  November  27th  were  merely  a  trail  which  the 
comet  left  behind. 

A  multitude  of  letters  were  read  at  the  last  and  previous 
meeting  of  the  Astronomical  Society,  in  which  the  writers 
described  the  details  of  their  own  observations.  As  these 
letters  came  from  nearly  all  parts  of  the  world,  the  data 
have  an  unusual  degree  of  completeness,  and  show  very 


112  SCIENCE  IN  SHORT  CHAPTERS. 

strikingly  the  yalue  of  the  work  of  amateur  astronomical 
observers. 

By  the  collation  and  comparison  of  these,  important  in- 
ductions are  obtainable.  Thus  Professor  A.  S.  Herschel 
concludes  that  the  earth  passed  through  seven  strata  of 
meteoric  bodies,  having  each  a  thickness  of  about  50,000 
miles — in  all  about  350,000  miles.  As  the  diameter  of  the 
visible  nebulosity  of  Biela's  comet  was  but  40,000  miles 
when  nearest  the  earth  in  1832,  the  great  thickness  of  these 
strata  indicates  something  beyond  the  comet  itself. 

Besides  this,  Mr.  Hind's  calculation  for  the  return  of 
the  primary  comet  shows  that  on  November  27th  it  was  250 
millions  of  miles  from  the  earth. 

Those,  however,  who  are  determined  to  enjoy  the  sen- 
sation of  supposing  that  they  really  have  been '  brushed  by 
the  tail  of  a  comet,  still  have  the  secondary  comet  to  fall 
back  upon.  This,  as  already  described,  was  broken  off 
the  original,  from  which  it  was  seen  gradually  to  diverge, 
but  was  still  linked  to  it  by  an  arch  of.  nebulous  matter. 

If  this  divergence  has  continued,  it  must  now  be  far  dis- 
tant— sufficiently  far.  to  afford  me  an  opportunity  of  safely 
adding  another  to  the  numerous  speculations,  viz.,  that  we 
may,  on  November  27th,  have  plunged  obliquely  through 
this  connecting  arm  of  nebulous  matter,  which  was  seen 
stretching  between  the  parent  comet  and  its  offshoot.  The 
actual  position  of  the  meteoric  strata  above  referred  to  is 
quite  consistent  with  the  hypothesis. 


THE  "GKEAT  ICE  AGE"  AND   THE  OEIGIN  OF 
THE  "TILL." 

THE  growth  of  science  is  becoming  so  overwhelming  that 
the  old  subdivisions  of  human  knowledge  are  no  longer 
sufficient  for  the  purpose  of  dividing  the  labor  of  experts. 
It  is  scarcely  possible  now  for  any  man  to  become  a  natu- 
ralist, a  chemist,  or  a  physicist  in  the  full  sense  of  either 
term;  he  must,  if  he  aims  at  thoroughness,  be  satisfied 


THE  "  GREAT  ICE  AGE."  113 

with  a  general  knowledge  of  the  great  body  of  science,  and 
a  special  and  a  full  acquaintance  with  only  one  or  two  of  its 
minor  subdivisions.  Thus  geology,  though  but  a  branch 
of  natural  history,  and  the  youngest  of  its  branches,  has 
now  become*  so  extensive  that  its  ablest  votaries  are  com- 
pelled to  devote  their  best  efforts  to  the  study  of  sections 
which  but  a  few  years  ago  were  scarcely  definable. 

Glaciation  is  one  of  these,  which  now  demands  its  own 
elementary  text-books  over  and  above  the  monographs  of 
original  investigators.  This  demand  has  been  well  sup- 
plied by  Mr.  James  Geikie  in  the  "  The  Great  Ice  Age,"  * 
of  which  a  second  edition  has  just  been  issued.  Every 
student  of  glacial  phenomena  owes  to  Mr.  Geikie  a  heavy 
debt  of  gratitude  for  the  invaluable  collection  of  facts  and 
philosophy  which  this  work  presents.  It  may  now  be 
fairly  described  as  a  standard  treatise  on  the  subject  which 
it  treats. 

One  leading  feature  of  the  work  offers  a  very  aggressive 
invitation  to  criticism.  Scotchmen  are  commonly  accused 
of  looking  upon  the  whole  universe  through  Scotch  spec- 
tacles, and  here  we  have  a  Scotchman  treating  a  subject 
which  affects  nearly  the  whole  of  the  globe,  and  devoting 
abont  half  of  his  book  to  the  details  of  Scottish  glacial  de- 
posits; while  England  has  but  one-third  of  the  space  al- 
lowed to  Scotland,  Ireland  but  a  thirtieth,  Scandinavia 
less  than  a  tenth,  North  America  a  sixth,  and  so  on  with 
the  rest  of  the  world.  Disproportionate  as  this  may  ap- 
pear at  first  glance,  further  acquaintance  with  the  work 
justifies  the  pre-eminence  which  Mr.  Geikie  gives  to  the- 
Scotch  glacial  deposits.  Excepting  Norway,  there  is  no 
country  in  Europe  which  affords  so  fine  a  field  for  the 
study  of  the  vestiges  of  extinct  glaciers  as  Scotland,  am} 
Scotland  has  an  advantage  even  over  Norway  in  being 
much  better  known  in  geological  detail. ,  Besides  this,  we 
must  always  permit  the  expounder  of  any  subject  to  select 
his  own  typical  illustrations,  and  welcome  his  ability  to 

*  "  The  Great  Ice  Age,  and  its  Relation  to  the  Antiquity  of  Man." 
By  James  Geikie,  P.R.S.,  etc.  Second  edition,  revised,  1877. 
Daldy  and  Isbister. 


114  SCIENCE  IN  SHORT  CHAPTERS. 

find  them  in  a  region  which  he  himself  has  directly  ex- 
plored. 

Mr.  Geikie's  connection  with  the  geological  survey  of 
Scotland  has  afforded  him  special  facilities  for  making  good 
use  of  Scottish  typical  material,  and  he  has  turned  these 
opportunities  to  such  excellent  account  that  no  student 
after  reading  "  The  Great  Ice  Age"  will  find  fault  with  its 
decided  nationality. 

The  leading  feature — the  basis,  in  fact — of  this  work  de- 
serves especial  notice,  as  it  gives  it  a  peculiar  and  timely 
value  of  its  own.  This  feature  is  that  the  subject — as  com- 
pared with  its  usual  treatment  by  other  leading  writers — is 
turned  round  and  presented,  so  to  speak,  bottom  upwards. 
De  Saussure,  Charpentier,  Agassiz,  Humboldt,  Forbes, 
Hopkins,  Whewell,  Stark,  Tyndall,  etc.,  have  studied  the 
living  glaciers,  and  upon  the  data  thus  obtained  have  iden- 
tified the  work  of  extinct  glaciers.  Chronologically  speak- 
ing, they  have  proceeded  backwards,  a  method  absolutely 
necessary  in  the  early  stages  of  the  inquiry,  and  which  has 
yielded  admirable  results.  Geikie,  in  the  work  before  us, 
proceeds  exactly  in  the  opposite  order.  Availing  himself 
of  the  means  of  identifying  glacial  deposits  which  the  re- 
trogressive method  affords,  he  plunges  at  once  to  the  lowest 
and  oldest  of  these  deposits,  which  he  presents  the  most 
prominently,  and  then  works  upwards  and  onwards  to  re- 
cent glaciation. 

The  best  illustration  I  can  offer  of  the  timely  advantage 
of  this  reversed  treatment  is  (with  due  apology  for  neces- 
'sary  egotism)  to  state  my  own  case.  In  1841,  when  the 
"glacial  hypothesis,"  as  it  was  then  called,  was  in  its  in- 
fancy, Professor  Jamieson,  although  very  old  and  nearly  at 
the  end  of  his  career,  took  up  the  subject  with  great  en- 
thusiasm, and  devoted  to  it  a  rather  disproportionate  num- 
ber of  lectures  during  his  course  on  Natural  History.  Like 
many  of  his  pupils,  I  became  infected  by  his  enthusiasm, 
and  went  from  Edinburgh  to  Switzerland',  where  I  had  the 
good  fortune  to  find  Agassiz  and  his  merry  men  at  the 
"Hotel  des  Neufchatelois" — two  tents  raised  upon  a  mag- 
nificent boulder  floating  on  the  upper  part  of  the  Aar  gla- 
gier.  After  a  short  but  very  active  sojourn  there  I  (l  did," 


THE  "  GREAT  ICE  AGE."  115 

not  without  physical  danger,  many  other  glaciers  in  Swit- 
zerland and  the  Tyrol,  and  afterwards  practically  studied 
the  subject  in  Norway,  Nortfl^Wales,  and  wherever  else  an 
opportunity  offered,  reading  in  the  meantime  much  of  its 
special  literature  ;  but,  like  many  others,  confining  my  read- 
ing chiefly  to  authors  who  start  with  living  glaciers  and 
describe  their  doings  most  prominently.  "When,  however, 
I  read  the  first  edition  of  Mr.  Geikie's  "  Great  Ice  Age," 
immediately  after  its  publication,  his  mode  of  presenting 
the  phenomena,  bottom  upwards,  suggested  a  number  of 
reflections  that  had  never  occurred  before,  leading  to  other 
than  the  usual  explanations  of  many  glacial  phenomena, 
and  correcting  some  errors  into  which  I  had  fallen  in 
searching  for  the  vestiges  of  ancient  glaciers.  As  these 
suggestions  and  corrections  may  be  interesting  to  others,  as 
they  have  been  to  myself,  I  will  here  state  them  in  outline. 
The  most  prominent  and  puzzling  reflection  or  conclu- 
sion suggested  by  reading  Mr.  Geikie's  description  of  the 
glacial  deposits  of  Scotland  was,  that  the  great  bulk  of 
them  are  quite  different  from  the  deposits  of  existing  gla- 
ciers. This  reminded  me  of  a  previous  puzzle  and  disap- 
pointment that  I  had  met  in  Norway,  where  I  had  observed 
such  abundance  of  striation,  such  universality  of  polished 
rocks  and  rounded  mountains,  and  so  many  striking  exam- 
ples of  perched  blocks,  with  scarcely  any  decent  vestiges  of 
moraines.  This  was  especially  the  case  in  Arctic  Norway. 
Coasting  from  Trondhjem  to  Hammerfest,  winding  round 
glaciated  islands,  in  and  out  of  fjords  banked  with  glaciated 
rock-slopes,  along  more  than  a  thousand  miles  of  shore  line, 
displaying  the  outlets  of  a  thousand  ancient  glacier  valleys, 
scanning  eagerly  throughout  from  sea  to  summit,  landing 
at  several  stations,  and  climbing  the  most  commanding 
hills,  I  saw  only  one  ancient  moraine — that  at  the  Oxfjord 
station  described  in  "  Through  Norway  with  Ladies."  * 

*  The  terminal  moraine  at  the  Oxfjord  station,  which  I  have  al- 
ready mentioned  as  the  only  ancient  example  of  an  ordinary  moraine 
that  I  have  seen  in  Arctic  Norway,  "was,  of  course,  a  special  object 
of  interest  to  me.  Further  observation  showed  that  it  does  not 
merely  consist  of  the  heap  of  stones  I  noticed  in  1856,  which  appears 
like  a  disturbed  talus  cut  through  and  heaped  up  at  its  lower  part, 


116  SCIENCE  IN  SHORT  CHAPTERS. 

But  this  negative  anomaly  is  not  all.  The  ancient  gla- 
cial deposits  are  not  only  remarkable  on  account  of  the 
absence  of  the  most  characteristic  of  modern  glacial  de- 
posits, but  in  consisting  mainly  of  something  which  is  quite 
different  from  any  of  the  deposits  actually  formed  by  any 
of  the  modern  glaciers  of  Switzerland  or  any  other  country 
within  the  temperate  zones. 

I  have  seen  nothing  either  at  the  foot  or  the  sides  of  any 
living  Alpine  or  Scandinavian  glacier  that  even  approxi- 
mately represents  the  "till"  or  "boulder  clay,"  nor  any 
description  of  such  a  formation  by  any  other  observer ;  and 
have  met  with  no  note  of  this  very  suggestive  anomaly  by 
any  writer  on  glaciers.  Yet  the  till  and  bowlder  clay  form 
vast  deposits,  covering  thousands  of  square  miles  even  of 
the  limited  area  of  the  British  Isles,  and  constitute  the 
main  evidence  upon  which  we  base  all  our  theories  respect- 
ing the  existence  and  the  vast  extent  and  influence  of  the 
"Great  Ice  Age." 

Although  so  different  from  anything  at  present  produced 
by  the  Alpine  or  Scandinavian  glaciers,  this  great  deposit 
is  unquestionably  of  glacial  origin.  The  evidences  upon 
which  this  general  conclusion  rests  are  fully  stated  by  Mr. 

but  that  there  is  another  moraine  adjoining  it,  or  in  continuation 
with  it,  which  is  covered  with  vegetation,  and  stretches  quite  across 
the  mouth  of  the  valley.  The  Duke  of  Roxburgh,  who  is  well  ac- 
quainted with  this  neighborhood,  having  spent  sixteen  summers  in 
Arctic  Norway,  was  one  of  our  fellow-passengers,  and  told  me  that 
this  moraine  forms  a  barrier  that  dams  up  the  waters  of  a  considera- 
ble lake,  abounding  with  remarkably  fine  char.  I  learned  this  just 
as  the  packet  was  starting,  too  late  to  go  on  shore  even  for  a  few 
minutes,  and  obtain  a  view  of  this  lake  and  the  valley  beyond.  This 
I  regret,  as  it  might  have  revealed  some  explanation  of  the  excep- 
tional nature  of  this  moraine.  It  would  be  interesting  to  learn 
whether  it  belongs  to  the  greater  ice  age,  or  to  that  period  of  minor 
glaciation  that  fashioned  the  farm  patches  already  described.  The 
formation  of  the  lake  is  easily  understood  in  the  latter  case.  It  is 
only  required  that  such  a  minor  reglaciated  valley  as  one  of  these 
should  be  of  larger  magnitude  and  of  very  gentle  inclination  at  its 
lower  part,  so  that  the  secondary  glacier  should  die  out  before  reach- 
ing the  present  seashore.  It  would  then  deposit  its  moraine  across  the 
mouth  of  the  valley,  and  this  moraine  would  dam  up  the  waters 
which  such  a  valley  must  necessarily  receive  from  the  drainage  of  its 
hilly  sides.  Llyn  Idwal,  in  North  Wales,  is  a  lake  thus  formed, 


THE  "GREAT  ICE  AGE."  117 

Geikie,  and  may  safely  be  accepted  as  incontrovertible. 
Whence,  then,  the  great  difference  ? 

One  of  the  suggestions  to  which  I  have  already  alluded 
as  afforded  by  reading  Mr.  Geikie's  book  was  a  hypothetical 
solution  of  this  difficulty,  but  the  verification  of  the  hypo- 
thesis demanded  *  re-visit  to  Norway.  An  opportunity  for 
this  was  afforded  in  the  summer  of  1874,  during  which  I 
traveled  round  the  coast  from  Stavanger  to  the  Arctic 
frontier  of  Kussia,  and  through  an  interesting  inland  dis- 
trict. The  observations  there  made  and  strengthened  by 
subsequent  reflections,  have  so  far  confirmed  my  original 
speculative  hypothesis  that  I  now  venture  to  state  it  briefly 
as  follows  : 

That  the  period  appropriately  designated  by  Mr.  Geikie 
as  the  "  Great  Ice  Age"  includes  at  least  two  distinct  pe- 
riods or  epochs — the  first  of  very  great  intensity  or  magni- 
tude, during  which  the  Arctic  regions  of  our  globe  were  as 
completely  glaciated  as  the  Antarctic  now  are,  and  the 
British  islands  and  a  large  portion  of  Northern  Europe 
were  glaciated  as  completely,  and  nearly  in  the  same  man- 
ner, as  Greenland  is  at  the  present  time;  that  long  after 
this,  and  immediately  preceding  the  present  geological 
epoch,  there  was  a  minor  glacial  period,  when  only  the  now 
existing  valleys,  favorably  shaped  and  situated  for  glacial 
accumulations,  were  partially  or  wholly  filled  with  ice. 
There  may  have  been  many  intermediate  fluctuations  of 
climate  and  glaciation,  and  probably  were  such,  but  as 
these  do  not  affect  my  present  argument  they  need  not  be 
here  considered. 

So  far  I  agree  with  the  general  conclusions  of  Mr.  Geikie 
as  I  understand  them,  and  with  the  generally  received  hy- 
potheses, but  in  what  follows  I  have  ventured  to  diverge 
materially. 

It  appears  to  me  that  the  existing  Antarctic  glaciers  and 
some  of  the  glaciers  of  Greenland  are  essentially  different 
in  their  conformation  from  the  present  glaciers  of  the  Alps, 
and  from  those  now  occupying  some  of  the  f jelds  and  val- 
leys of  Norway;  and  that  the  glaciers  of  the  earlier  or 
greater  glacial  epoch  were  similar  to  those  now  forming  the 
Antarctic  barrier,  while  the  glaciers  of  the  later  or  minor 


118  SCIENCE  IN  SHORT  CHAPTERS. 

glacial  epoch  resembled  those  now  existing  in  temperate 
climates,  or  were  intermediate  between  these  and  the  Ant- 
arctic glaciers.  The  nature  of  the  difference  which  I  sup- 
pose to  exist  between  the  two  classes  of  glaciers  is  this  :  The 
glaciers  (properly  so  called)  of  temperate  climates  are  the 
overflow  of  the  neve  (the  great  reservoir»of  ice  and  snow 
above  the  snow  line).  They  are  composed  of  ice  which  is 
protruded  below  the  snow-line  into  the  region  where  the 
summer  thaw  exceeds  the  winter  snow-fall.  This  ice  is 
necessarily  subject  to  continual  thinning  or  wasting  from 
its  upper  or  exposed  surface,  and  thus  finally  becomes 
liquefied,  and  is  terminated  by  direct  solar  action. 

Many  of  the  characteristic  phenomena  of  Alpine  glaciers 
depend  upon  this  ;  among  the  more  prominent  of  which  are 
the  superficial  extrusion  of  boulders  or  rock  fragments  that 
have  been  buried  in  the  neve  or  have  fallen  into  the  crevasses 
of  the  upper  part  of  the  true  glacier,  and  the  final  deposit 
of  these  same  boulders  of  fragments  at  the  foot  of  the  gla- 
ciers forming  ordinary  moraines. 

But  this  is  not  all.  The  thawing  which  extrudes,  and 
finally  deposits  the  larger  fragments  of  rock,  sifts  from 
them  the  smaller  particles,  the  aggregate  bulk  of  which 
usually  exceeds  very  largely  that  of  the  larger  fragments. 
This  fine  silt  or  sand  thus  washed  away  is  carried  by  the 
turbid  glacier  torrent  to  considerable  distances,  and  de- 
posited as  an  alluvium  wherever  the  agitated  waters  find  a 
resting-place. 

Thus  the  debris  of  the  ordinary  modern  glacier  is  effec- 
tively separated  into  two  or  more  very  distinct  deposits  ;  the 
moraine  at  the  glacier  foot  consisting  of  rock  fragments  of 
considerable  size  with  very  little  sand  or  clay  or  other  tine 
deposit  between  them,  and  a  distant  deposit  of  totally  dif- 
ferent character,  consisting  of  gravel,  sand,  clay,  or  mud, 
according  to  the  length  and  conditions  of  its  journey.  The 
"chips,"  as  they  have  been  well  called,  are  thus  separated 
from  what  I  may  designate  the  filings  or  sawdust  of  the 
glacier. 

The  filings  from  the  existing  glaciers  of  the  Bernese  Alps 
are  gradually  filling  up  the  lake-basins  of  Geneva  and  Con- 
stance, repairing  the  breaches  made  by  the  erosive  action  of 


TEE  "  GREAT  ICE  AGE."  119 

their  gigantic  predecessors ;  those  of  the  southern  slope  of 
the  Alps  are  doing  a  large  share  in  filling  up  the  Adriatic  ; 
while  the  chips  of  all  merely  rest  upon  the  glacier  beds 
forming  the  comparatively  insignificant  terminal  moraine 
deposits. 

The  same  in  Scandinavia.  The  Storelv  of  the  Jostedal 
is  fed  by  the  melting  of  the  Krondal,  Nygaard,  Bjornestegs, 
and  soldal  glaciers.  It  has  filled  up  a  branch  of  the  deep 
Sogne  fjord,  forming  an  extensive  fertile  plain  at  the  mouth 
of  its  wild  valley,  and  is  depositing  another  subaqueous 
plain  beyond,  while  the  moraines  of  the  glaciers  are  but  in- 
considerable and  comparatively  insignificant  heaps  of  loose 
boulders,  spread  out  on  the  present  and  former  shores  of  the 
above-named  glaciers,  which  are  overflows  from  one  side  of 
the  great  neve,  the  Jostedal  Sneefond.  All  of  these  glaciers 
flow  down  small  lateral  valleys,  spread  out,  and  disappear 
in  the  main  valley,  which  has  now  no  glacier  of  its  own, 
though  it  was  formerly  glaciated  throughout. 

What  must  have  been  the  condition  of  this  and  the  other 
great  Scandinavian  valleys  when  such  was  the  case  ?  To 
answer  this  question  rationally  we  must  consider  the  meteoro- 
logical conditions  of  that  period.  Either  the  climate  must 
have  been  much  colder,  or  the  amount  of  precipitation 
vastly  greater  than  at  present,  in  order  to  produce  the  gene- 
ral glaciation  that  rounded  the  mountains  up  to  a  height  of 
some  thousands  of  feet  above  the  present  sea-level.  Probably 
both  factors  co-operated  to  effect  this  vast  glaciation,  the 
climate  colder,  and  the  snow-fall  also  greater.  The  whole 
of  Scandinavia,  or  as  much  as  then  stood  above  the  sea, 
must  have  been  a  neve  or  sueefond  on  which  the  annual 
snow-fall  exceeded  the  annual  thaw. 

This  is  the  case  at  present  on  the  largest  neve  of  Europe, 
the  500  square  miles  of  the  great  plateau  of  the  Jostedals 
and  Nordf jords  Sneefond,  on  all  the  overflowing  neve  or 
snow-fields  of  the  Alps  above  the  snow -line;  over  the  greater 
part  of  Greenland;  and  (as  the  structure  of  the  southern 
icebergs  prove)  everywhere  within  the  great  Antarctic  ice 
barrier. 

What,  then,  must  happen  when  the  snow-line  comes 
down,  or  nearly  down,  to  the  sea-level  ?  It  is  evident  that 


120  SCIENCE  IN  SHORT  CHAPTERS. 

the  out-thrust  glaciers,  the  overflow  down  the  valleys,  can- 
not come  to  an  end  like  the  present  Swiss  and  Scandinavian 
glaciers,  by  the  direct  melting  action  of  the  sun.  They  may 
be  somewhat  thinned  from  below  by  the  heat  of  the  earth, 
and  that  generated  by  their  own  friction  on  the  rocks,  but 
these  must  be  quite  inadequate  to  overcome  the  perpetual 
accumulation  due  to  the  snow-fall  upon  their  own  surface 
and  the  vast  overflow  from  the  great  snow-fields  above. 
They  must  go  on  and  on,  ever  increasing,  until  they  meet 
some  new  condition  of  climate  or  some  other  powerful 
agent  of  dissipation— something  that  can  effectively  melt 
them. 

This  agent  is  very  near  at  hand  in  the  case  of  the  Scan- 
dinavian valleys  and  those  of  Scotland.  It  is  the  sea.  I 
think  I  may  safely  say  that  the  valley  glaciers  of  these 
countries  during  the  great  ice  age  must  have  reached  the 
sea,  and  there  have  terminated  their  existence,  just  as  the 
Antarctic  glaciers  terminate  at  the  present  Antarctic  ice- 
wall. 

What  must  happen  when  a  glacier  is  thus  thrust  out  to 
sea?  This  question  is  usually  answered  by  assuming  that 
it  slides  along  the  bottom  until  it  reaches  such  a  depth  that 
notation  commences  and  then  it  breaks  off  or  "calves"  as 
icebergs.  This  views  is  strongly  expressed  by  Mr.  Geikie 
(p.  47)  when  he  says  that — "  The  seaward  portion  of  an 
.  Arctic  glacier  cannot  by  any  possibility  be  floated  up  with- 
out sundering  its  connection  with  the  frozen  mass  behind. 
So  long  as  the  bulk  of  the  glacier  much  exceeds  the  depth 
of  the  sea,  the  ice  will  of  course  rest  upon  the  bed  of  the 
fjord  or  bay  without  being  subjected  to  any  strain  or  tension. 
But  when  the  glacier  creeps  outwards  to  greater  depths, 
then  the  superior  specific  gravity  of  the  sea- water  will  tend 
to  press  the  ice  upward'.  That  ice,  however,  is  a  hard  con- 
tinuous mass,  with  sufficient  cohesion  to  oppose  for  a  time 
this  pressure,  and  hence  the  glacier  crawls  on  to  a  depth  far 
beyond  the  point  at  which,  had  it  been  free,  it  would  have 
risen  to  the  surface  and  floated.  If  at  this  great  depth  the 
whole  mass  of  the  glacier  could  be  buoyed  up  without 
breaking  off,  it  would  certainly  go  to  prove  that  the  ice  of 
Arctic  regions,  unlike  ice  anywhere  else,  had  the  property 


THE  "  GREAT  ICE  AGE."  121 

of  yielding  to  mechanical  strain  without  rupturing.  But 
the  great  tension  to  which  it  is  subjected  takes  effect  in  the 
usual  way,  and  the  ice  yields,  not  by  bending  and  stretch- 
ing, but  by  breaking."  Mr.  Geikie  illustrates  this  by  a 
diagram  showing  the  "  calving"  of  an  iceberg. 

In  spite  of  my  respect  for  Mr.  Geikie  as  a  geological  au- 
thority, I  have  no  hesitation  in  contradicting  some  of  the 
physical  assumptions  included  in  the  above. 

Ice  has  no  such  rigidity  as  here  stated.  It  does  possess 
in  a  high  degree  "the  property  of  yielding  to  mechanical 
strain  without  rupturing. "  We  need  not  go  far  for  evidence 
of  this.  Everybody  who  has  skated  or  seen  others  skating 
on  ice  that  is  but  just  thick  enough  to  "bear"  must  have 
felt  or  seen  it  yield  to  the  mechanical  strain  of  the  skater's 
weight.  Under  these  conditions  it  not  only  bends  under 
him,  but  it  afterwards  yields  to  the  reaction  of  the  water 
below,  rising  and  falling  in  visible  undulations,  demon- 
strating most  unequivocally  a  considerable  degree  of  flexi- 
bility. It  may  be  said  that  in  this  case  the  flexibility  is  due 
to  the  thinness  of  the  ice ;  but  this  argument  is  unsound, 
inasmuch  as  the  manifestation  of  such  flexibility  does  not 
depend  upon  absolute  thickness  or  thinness,  but  upon  the 
relation  of  thickness  to  superficial  extension.  If  a  thin 
sheet  of  ice  can  be  bent  to  a  given  arc,  a  thick  sheet  may 
be  bent  in  the  same  degree,  but  the  thicker  ice  demands  a 
greater  radius  and  proportionate  extension  of  circumference. 
But  we  have  direct  evidence  that  ice  of  great  thickness — 
actual  glaciers — may  bend  to  a  considerable  curvature  before 
breaking.  This  is  seen  very  strikingly  when  the  uncrevassed 
ice-sheet  of  a  slightly  inclined  neve  suddenly  reaches  a  pre- 
cipice and  is  thrust  over  it.  If  Mr.  Geikie  were  right,  the 
projecting  cornice  thus  formed  should  stand  straight  out, 
and  then,  when  the  transverse  strain*  due  to  the  weight  of 
this  rigid  overhang  exceeded  the  resistance  of  tenacity,  it 
should  break  off  short,  exposing  a  face  at  right  angles  to 
the  general  surface  of  the  supported  body  of  ice.  Had 
Mr.  Geikie  ever  seen  and  carefully  observed  such  an  over- 
hang or  cornice  of  ice,  I  suspect  that  the  above-quoted  pas- 
sage would  not  have  been  written. 

Some  very  fine  examples  of  such  ice-cornices  are  well  seen 


122  SCIENCE  IN  SHORT  CHAPTERS. 

from  the  ridge  separating  the  Handspikjen  Fjelde  from  the 
head  of  the  Jostedal,  where  a  view  of  the  great  neve  or 
sneefond  is  obtained.  This  side  of  the  neve  terminates  in 
precipitous  rock- walls;  at  the  foot  of  one  of  these  is  a  dreary 
lake,  the  Styggevand.  The  overflow  of  the  neve  here  forms 
great  bending  sheets  that  reach  a  short  way  down,  and  then 
break  off  and  drop  as  small  icebergs  into  the  lake.* 

The  ordinary  course  of  glaciers  affords  abundant  illustra- 
tions of  the  plasticity  of  such  masses  of  ice.  They  spread 
out  where  the  valley  widens,  contract  where  the  valley 
narrows,  and  follow  all  the  convexities  or  concavities  of  the 
axial  line  of  its  bed.  If  the  bending  thus  enforced  exceeds 
a  certain  degree  of  abruptness  crevasses  are  formed,  but  a 
considerable  bending  occurs  before  the  rupture  is  effected, 
and  crevasses  of  considerable  magnitude  are  commonly 
formed  without  severing  one  part  of  a  glacier  from  another. 
They  are  usually  V-shaped,  in  vertical  section,  and  in  many 
the  rupture  does  not  reach  the  bottom  of  the  glacier.  Very 
rarely  indeed  does  a  crevasse  cross  the  whole  breadth  of  a 
glacier  in  such  a  manner  as  to  completely  separate,  even 
temporarily,  the  lower  from  the  upper  part  of  the  glacier. 

If  a  glacier  can  thus  bend  downwards  without  "sunder- 
ing its  connection  with  the  frozen  mass  behind,"  surely  it 
may  bend  upwards  in  a  corresponding  degree,  either  with 
or  without  the  f  oraiation  of  crevasses,  accoring  to  the  thick- 
ness of  the  ice  and  the  degree  of  curvature. 

A  glacier  reaching  the  sea  by  a  very  steep  incline  would 
probably  break  off,  in  accordance  with  Mr.  Geikie's  descrip- 
tion, just  as  an  Alpine  glacier  is  ruptured  fairly  across  when 
it  makes  a  cascade  over  a  suddely  precipitous  bend  of  its 
path.  One  entering  the  sea  at  an  inclination  somewhat 
less  precipitous  than  the  minor  limit  of  the  effective  rupture 
gradient  would  be  crevassed  in  a  contrary  manner  to  the 
crevassing  of  Alpine  glaciers.  Its  crevasses  would  gape 
downwards  instead  of  upwards — have  A-shaped  instead  of 
a  V-shaped  section. 

With  a  still  more  moderate  slope,  the  up-floating  of  the 

*  See  "  Through  Norway  with  a  Knapsack,"  chapters  xi.  and  xii., 
for  further  descriptions  of  these. 


THE  "GREAT  ICE  AGE."  123 

termination  of  the  glacier,  and  a  concurrent  general  up-lift- 
ing or  up  bending  of  the  whole  of  its  submerged  portion 
might  occur  without  even  a  partial  rupture  or  crevasse 
formation  occurring. 

Let  us  now  follow  out  some  of  the  necessary  results  of 
these  conditions  of  glacier  existence  and  glacial  prolonga- 
tion. The  first  and  most  notable,  by  its  contrast  with  ordi- 
nary glaciers,  is  the  absence  of  lateral,  medial,  or  terminal 
moraines.  The  larger  masses  of  debris,  the  chippings  that 
may  have  fallen  from  the  exposed  escarpments  of  the 
mountains  upon  the  surface  of  the  upper  regions  of  the 
glacier,  instead  of  remaining  on  the  surface  of  the  ice  and 
standing  above  its  general  level  by  protecting  the  ice  on 
which  they  rest  from  the  general  snow-thaw,  would  become 
buried  by  the  upward  accretion  of  the  ice  due  to  the  un- 
thawed  stratum  of  each  year's  snow-fall. 

The  thinning  agency  at  work  upon  such  glaciers  during 
their  journey  over  the  terra  firma  being  the  outflow  of  ter- 
restrial heat  and  that  due  to  their  friction  upon  their  beds, 
this  thinning  must  all  take  place  from  below,  and  thus,  as 
the  glaciers  proceed  downwards,  these  rock  fragments  must 
be  continually  approaching  the  bottom  instead  of  continu- 
ally approaching  the  top,  as  in  the  case  of  modern  Alpine 
glaciers  flowing  below  the  snow-line,  and  thawing  from 
surface  downwards. 

It  follows,  therefore,  that  such  glaciers  could  not  deposit 
any  moraines  such  as  are  in  course  of  deposition  by  existing 
Alpine  and  Scandinavian  glaciers. 

What,  then,  must  become  of  the  chips  and  filings  of 
these  outfloatiug  glaciers?  They  must  be  carried  along 
with  the  ice  so  long  as  that  ice  rests  upon  the  land  ;  for  this 
debris  must  consist  partly  of  fragments  imbedded  in  the  ice, 
and  partly  of  ground  and  re-ground  excessively  subdivided 
particles,  that  must  either  cake  into  what  I  may  call  ice- 
mud,  and  become  a  part  of  the  glacier,  or  flow  as  liquid  mud 
or  turbid  water  beneath  it,  as  with  ordinary  glaciers.  The 
quantity  of  water  being  relatively  small  under  the  supposed 
conditions,  the  greater  part  would  be  carried  forward  to 
the  sea  by  the  ice  rather  than  by  the  water. 

An  important  consequence  of  this  must  be  that  the 


124  SCIENCE  IN  SHORT  CHAPTERS. 

erosive  power  of  these  ancient  glaciers  was,  cceteris  paribus, 
greater  than  that  of  modern  Alpine  glaciers,  especially  if 
we  accept  those  theories  which  'ascribe  an  actual  internal 
growth  or  regeneration  of  glaciers  by  the  relegation  below 
of  some  of  the  water  resulting  from  the  surface-thaw. 

As  the  glacier  with  its  lower  accumulation  advances  into 
deeper  and  deeper  water,  its  pressure  upon  its  bed  must 
progressively  diminish  until  it  reaches  a  line  where  it  would 
just  graze  the  bottom  with  a  touch  of  feathery  lightness. 
Somewhere  before  reaching  this  it  would  begin  to  deposit 
its  burden  on  the  sea-bottom,  the  commencement  of  this 
deposition  being  determined  by  the  depth  whereat  the  tena- 
city of  the  deposit,  or  its  friction  against  the  sea-bottom,  or 
both  combined,  becomes  sufficient  to  overpower  the  now- 
diminished  pressure  and  forward  thrusting,  or  erosive  power 
of  the  glacier. 

Father  forward,  in  deeper  water,  where  the  ice  becomes 
fairly  floated  above  the  original  sea-bottom,  a  rapid  under- 
thawing  must  occur  by  the  action  of  the  sea-water,  and  if 
any  communication  exists  between  this  ice  covered  sea  and 
the  waters  of  warmer  latitudes  this  thawing  must  be  in- 
creased by  the  currents  that  would  necessarily  be  formed  by 
the  interchange  of  water  of  varying  specific  gravities.  De- 
position would  thus  take  place  in  this  deeper  water,  contin- 
ually shallowing  it  or  bringing  up  the  sea-bottom  nearer  to 
the  ice-bottom. 

This  raising  of  the  sea-bottom  must  occur  not  only  here, 
but  farther  back,  i.e.,  from  the  limit  at  which  deposition 
commenced.  This  neutral  ground,  whereat  the  depth  is 
just  sufficient  to  allow  the  ice  to  rest  lightlj7  on  its  own  de- 
posit and  slide  over  it  without  either  sweeping  it  forward 
or  depositing  any  more  upon  it,  becomes  an  interesting 
critical  region,  subject  to  continuous  forward  extension  dur- 
ing the  lifetime  of  the  glacier,  as  the  deposition  beyond  it 
must  continually  raise  the  sea-bottom  until  it  reaches  the 
critical  depth  at  which  the  deposition  must  cease.  This 
would  constitute  what  I  may  designate  the  normal  depth  of 
the  glaciated  sea,  or  the  depth  towards  which  it  would  be 
continually  tending,  during  a  great  glacial  epoch,  by  the 
formation  of  a  submarine  bank  or  plain  of  glacier  deposit, 


THE  '"  GREAT  ICE  A6E."  125 

over  which  the  glacier  would  slide  without  either  grinding 
it  lower  by  erosion  or  raising  it  higher  by  deposition. 

But  what  must  be  the  nature  of  this  deposit  ?  It  is  evi- 
dent that  it  cannot  be  a  mere  moraine  consisting  only  of  the 
larger  fragments  of  rock  such  as  are  now  deposited  at  the 
foot  of  glaciers  that  die  out  before  reaching  the  sea.  Nei- 
ther can  it  correspond  to  the  glacial  silt  which  is  washed 
away  and  separated  from  these  larger  fragments  by  glacial 
streams,  and  deposited  at  the  outspreadings  of  glacier  tor- 
rents and  rivers.  It  will  correspond  to  neither  the  assorted 
gravel,  sand,  nor  mud  of  these  alluvial  deposits,  but  must 
be  an  agglomeration  of  all  the  infusible  solid  matter  the 
gacier  is  capable  of  carrying. 

It  must  contain,  in  heterogeneous  admixture,  the  great 
boulders,  the  lesser  rock  fragments,  the  gravel  chips,  the 
sand,  and  the  slimy  mud;  these  settling  down  quietly  in 
the  cold,  gloomy  waters,  overshadowed  by  the  great  ice- 
sheet,  must  form  just  such  an  agglomeration  as  we  find  in 
the  boulder  clay  and  tills,  and  lie  just  in  those  places  where 
these  deposits  abound,  provided  the  relative  level  of  land 
and  sea  during  the  glacial  epoch  were  suitable. 

I  should  make  one  additional  remark  relative  to  the 
composition  of  this  deposit,  viz.,  that  under  the  conditions 
supposed,  the  original  material  detached  from  the  rocks 
around  the  upper  portions  of  the  glaciers  would  suffer  a  far 
greater  degree  of  attrition  at  the  glacier  bottom  than  it  ob- 
tains in  modern  Alpine  glaciers,  inasmuch  as  in  these  it  is 
removed  by  the  glacier  torrent  when  it  has  attained  a  certain 
degree  of  fineness,  while  in  the  greater  glaciers  of  the 
glacial  epoch  it  would  be  carried  much  further  in  associa- 
tion with  the  solid  ice,  and  be  subjected  to  more  grinding 
and  regrinding  against  the  bottom.  Hence  a  larger  pro- 
portion of  slimy  inud  would  be  formed,  capable  of  finally 
induring  into  stiff  clay  such  as  forms  the  matrix  of  the  till 
and  boulder  clay. 

The  long  journey  of  the  bottom  debris  stratum  of  the 
glacier,  and  its  final  deposition  when  in  a  state  of  neutral 
equilibrium  between  its  own  tendency  to  repose  and  the 
forward  thrust  of  the  glacier,  would  obviously  tend  to  ar- 
range the  larger  fragments  of  rock  in  the  manner  in  which 


126  SCIENCE  IN  SHORT  CHAPTERS. 

they  are  found  imbedded  in  the  till,  i.e.,  the  oblong  frag- 
ments lying  with  their  longer  axes  and  their  best  marked 
striae  in  the  direction  of  the  motion  of  the  glacier.  The 
"striated  pavements"  of  the  till  are  thus  easily  explained; 
they  are  the  surface  upon  which  the  ice  advanced  when  its 
deposits  had  reached  the  critical  or  neutral  height.  Such 
a  pavement  would  continually  extend  outwards. 

The  only  sorting  of  the  material  likely  to  occur  under 
these  conditions  would  be  that  due  to  the  earlier  deposi- 
tion and  entanglement  of  the  larger  fragments,  thus  pro- 
ducing a  more  stony  deposit  nearer  inland,  just  as  Mr. 
Geikie  describes  the  actual  deposits  of  till  where,  "gener- 
ally speaking,  the  stones  are  most  numerous  in  the  till  of 
hilly  districts;  while  at  the  lower  levels  of  the  country  the 
clayey  character  of  the  mass  is  upon  the  whole  more  pro- 
nounced." These  "  hilly  districts,"  upon  the  supposition 
of  greater  submergence,  would  be  the  near  shore  regions, 
and  the  lower  levels  the  deeper  sea  where  the  glacier  floated 
freely. 

The  following  is  Mr.  Geikie's  description  of  the  distribu- 
tion of  the  till  (page  13) : — "  It  is  in  the  lower-lying  districts 
of  the  country  where  till  appears  in  greatest  force.  Wide 
areas  of  the  central  counties  are  covered  up  with  it  con- 
tinuously, to  a  depth  varying  from  two  or  three  feet  up  to 
one  hundred  feet  and  more.  But  as  we  follow  it  towards 
the  mountain  regions  it  becomes  thinner  and  more  inter- 
rupted— the  naked  rock  ever  and  anon  peering  through, 
until  at  last  we  find  only  a  few  shreds  and  patches  lying 
here  and  there  in  sheltered  hollows  of  the  hills.  Through- 
out the  Northern  Highlands  it  occurs  but  rarely,  and  only 
in  little  isolated  patches.  It  is  not  until  we  get  way  from 
the  steep  rocky  declivities  and  narrow  glens  and  gorges, 
and  enter  upon  the  broader  valleys  that  open  put  from  the 
base  of  the  highland  mountains  to  the  low-lying  districts 
beyond,  that  we  meet  with  any  considerable  deposits  of 
stony  clay.  The  higher  districts  of  the  Southern  Uplands 
are  almost  equally  free  from  any  covering  of  till.' 

This  description  is  precisely  the  same  as  I  must  have 
written,  had  I  so  far  continued  my  imaginary  sketch  of  the 
results  of  ancient  glaciation  as  to  picture  what  must  re- 


THE  "GREAT  IGE  AGE."  127 

main  after  the  glaciers  had  all  melted  away,  and  the  sea 
had  receded  sufficiently  to  expose  their  submarine  de- 
posits. 

Throughout  the  above  I  have  assumed  a  considerable 
submergence  of  the  land  as  compared  with  the  present  sea- 
level  on  the  coasts  of  Scotland,  Scandinavia,  etc. 

The  universality  of  the  terraces  in  all  the  Norwegian 
valleys  opening  westward  proves  a  submergence  of  at  least 
600  or  700  feet.  When  I  first  visited  Norway  in  1856,  I 
accepted  the  usual  description  of  these  as  alluvial  deposits; 
was  looking  for  glacial  vestiges  in  the  form  of  moraines, 
and  thus  quite  failed  to  observe  the  true  nature  of  these 
vast  accumulations,  which  was  obvious  enough  when  I  re- 
examined  them  in  the  light  of  more  recent  information. 
Some  few  are  alluvial,  but  they  are  exceptional  and  of 
minor  magnitude.  As  an  example  of  such  alluvial  ter- 
races I  may  mention  those  near  the  mouth  of  the  Romsdal, 
that  are  well  seen  from  the  Aak  Hotel,  and  which  a  Rus- 
sian prince,  or  other  soldier  merely  endowed  with  military 
eyes,  might  easily  mistake  for  artificial  earthworks  erected 
for  the  defence  of  the  valley. 

In  this  case,  as  in  the  others  where  the  terraces  are  allu- 
vial, the  valley  is  a  narrow  one,  occupied  by  a  relatively 
wide  river  loaded  with  recent  glacial  debris.  It  evidently 
filled  the  valley  during  the  period  of  glacial  recession. 

The  ordinary  wider  valleys,  with  a  river  that  has  cut  a 
narrow  channel  through  the  outspread  terrace-flats,  display 
a  different  formation.  Near  the  mouth  of  such  valleys  I 
have  seen  cuttings  of  more  than  a  hundred  feet  in  depth, 
through  an  unbroken  terrace  of  most  characteristic  till, 
with  other  traces  rising  above  it.  This  is  the  ordinary 
constitution  of  the  lower  portions  of  most  of  the  Scandi- 
navian terraces. 

These  terraces  are  commonly  topped  with  quite  a  dif- 
ferent stratum,  which  at  first  I  regarded  as  a  subsequent 
alluvial  or  estuarine  deposit,  but  further  examination  sug- 
gested another  explanation  of  the  origin  of  some  por- 
tions of  this  superficial  stratum,  to  which  I  shall  refer 
hereafter. 

Such  terraces  prove  a  rise  of  sea  or  depression  of  land, 


128  SCIENCE  IN  SHORT  CHAPTERS. 

during  the  glacial  epoch,  to  the  extent  of  600  feet  as  a 
minimum,  while  the  well-known  deposits  of  Arctic  shells 
at  Moel  Tryfaen  and  the  accompanying  drift  have  led  Prof. 
Ramsay  to  estimate  "the  probable  amount  of  submergence 
during  some  part  of  the  glacial  period  at  about  2300 
feet."  * 

It  would  be  out  of  place  here  to  reproduce  the  data  upon 
which  geologists  have  based  their  rather  divergent  opinions 
respecting  the  actual  extent  of  the  submergence  of  the 
western  coast  of  North  Europe.  All  agree  that  a  great 
submergence  occurred,  but  differ  only  as  to  its  extent,  their 
estimates  varying  between  1,000  and  3,000  feet. 

There  is  one  important  consideration  that  must  not  be 
overlooked,  viz.,  that — if  my  view  of  the  submarine  origin 
of  the  till  be  correct — the  mere  submergence  of  the  land  at 
the  glacial  period  does  not  measure  the  difference  between 
the  depth  of  the  sea  at  that  and  the  present  time,  seeing 
that  the  deposits  from  the  glaciers  must  have  shallowed  it 
very  materially. 

It  is  only  after  contemplating  thoroughly  the  present 
form  of  the  granitic  and  metamorphic  hills  of  Scandinavia, 
— hills  that  are  always  angular  when  subjected  only  to  sub- 
aerial  weathering,— that  one  can  form  an  adequate  con- 
ception of  the  magnitude  of  this  shallowing  deposit.  The 
rounding,  shaving,  grinding,  planing,  and  universal  abra- 
sion everywhere  displayed  appear  to  me  to  justify  the  con- 
clusion that  if  the  sea  were  now  raised  to  the  level  of  the 
terraces,  i.e.,  600  feet  higher  than  at  present,  the  mass  of 
matter  abraded  from  the  original  Scandinavian  mountains, 
and  lying  under  the  sea,  would  exceed  the  whole  mass  of 
mountain  left  standing  above  it. 

The  first  question  suggested  by  reading  Mr.  Geikie's 
book  was  whether  the  terraces  are  wholly  or  partially 
formed  of  till,  and  more  especially  whether  their  lower 
portions  are  thus  composed.  This,  as  already  stated,  was 
easily  answered  by  the  almost  unanimous  reply  of  all  the 
many  Norwegian  valleys  I  traversed.  Any  tourist  may 
verify  this.  The  next  question  was  whether  this  same  tifi 

*Lyell,  "Elements  of  Geology,"  p.  159. 


THE  "GREAT  ICE  AGE."  129 

extends  below  the  sea.  This  was  not  so  easily  answered  by 
the  means  at  my  disposal,  as  I  travelled  hastily  round  the 
coast  from  Stavanger  via  the  North  Cape  to  the  frontier 
of  Russian  Lapland  in  ordinary  passenger  steam-packets,, 
which  made  their  stoppages  to  suit  other  requirements 
than  mine.  Still,  I  was  able  to  land  at  many  stations,  and 
found,  wherever  there  was  a  gently  sloping  strand  at  the. 
mouth  of  an  estuary,  or  of  a  valley  whose  river  had  already 
deposited  its  suspended  matter  (a  common  case  hereabouts, 
where  so  many  rivers  terminate  in  long  estuaries  or  open 
out  into  bag-shaped  lakes  near  the  coast),  and  where  the 
bottom  had  not  been  modified  by  secondary  glaciation,  that 
the  receding  tide  displayed  a  sea-bottom  of  till,  covered 
with  a  thin  stratum  of  loose  stones  and  shells.  In  some 
cases  the  tijl  was  so  bare  that  it  appeared  like  a  stiff  mud 
deposited  but  yesterday. 

At  Bodo,  an  arctic  coast  station  on  the  north  side  of  the 
mouth  of  the  Salten  fjord  (lat.  67°  20'),  where  the  packets 
make  a  long  halt,  is  a  very  characteristic  example  of  this; 
a  deposit  of  very  tough  till  forming  an  extensive  plain  just 
on  the  sea-level.  The  tide  rises  over  this,  and  the  wa*ves 
break  upon  it,  forming  a  sort  of  beach  by  washing  away 
some  of  the  finer  material,  and  leaving  the  stones  behind. 
The  ground  being  so  nearly  level,  the  reach  of  the  tide  is 
very  great,  and  thus  a  large  area  is  exposed  at  low  tide. 
Continuous  with  this,  and  beyond  the  limit  of  high  tide,  is 
an  extensive  inland  plain  covered  with  coarse  grass  and 
weeds  growing  directly  upon  the  surface  of  the  original  flat 
pavement  of  till. 

There  is  no  river  at  Bodo;  the  sea  is  clear,  leaves  no  ap- 
preciable deposit,  and  the  degree  of  denudation  of  the  clayey 
matrix  of  the  till  is  very  much  smaller  than  might  be  ex- 
pected. The  limit  of  high  water  is  plainly  shown  by  a  beach 
of  shells  and  stones,  but  at  low  tide  the  ground  over  which 
the  sea  has  receded  is  a  bare  and  scarcely  modified  surface 
of  till.  I  have  observed  the  same  at  low  water  at  many 
other  arctic  stations.  In  the  Tromso  Sund  there  are  shal- 
lows at  some  distance  from  the  shore  which  are  just  covered 
with  water  at  low  tide.  I  landed  and  waded  on  these,  and 
found  the  bottom  to  consist  of  till  covered  with  a  thin  layer 


130  SCIENCE  IN  SHORT  CHAPTERS. 

of  shells,  odd  fragments  of  earthenware,  and  other  rubbish 
thrown  overboard  from  vessels.  It  is  evident  that  breakers 
of  considerable  magnitude  are  necessary  for  the  loosening 
'of  this  tough  compact  deposit — that  it  is  very  slightly,  if  at 
all,  affected  by  the  mere  flow  of  running  water. 

I  specify  these  instances  as  characteristic  and  easy  of 
verification,  as  the  packets  all  stop  at  these  stations;  but  a 
yachtsman  sailing  at  leisure  amidst  the  glorious  coast  scenery 
of  the  Arctic  Ocean  might  multiply  such  observations  a 
hundredfold  by  stopping  wherever  such  strands  are  indi- 
cated in  passing.  I  saw  a  multitude  of  these  in  places  where 
I  was  unable  to  go  ashore  and  examine  them. 

A  further  question  in  this  direction  suggested  itself  on  the 
spot,  viz.,  what  is  the  nature  of  the  "  banks"  which  consti- 
tute the  fishing-grounds  of  Norway,  Iceland,  .Newfound- 
land, etc.  They  are  submarine  plains  unquestionably — they 
must  have  a  high  degree  of  fertility  in  order  to  supply  food 
for  the  hundreds  of  millions  of  voracious  cod-fish,  coal-fish, 
haddocks,  hallibut,  etc.,  that  people  them.  These  large 
fishes  all  feed  on  the  bottom,  their  chief  food  being  mollusca 
and  Crustacea,  which  must  and,  either  directly  or  indirectly, 
some  pasture  of  vegetable  origin.  The  banks  are,  in  fact, 
great  meadows  or  feeding  grounds  for  the  lower  animals 
which  support  the  higher. 

From  the  Lofoten  bank  alone  twenty  millions  of  cod-fish 
are  taken  annually,  besides  those  devoured  by  the  vast  mul- 
titude of  sea-birds.  Now  this  bank  is  situated  precisely 
where,  according  to  the  above-stated  view  of  the  origin  of 
the  till,  there  should  be  a  huge  deposit.  It  occupies  the 
Vest  fjord,  i.e.,  the  opening  between  the  mainland  and  the 
Lofoden  Islands,  extending  from  Moskenes,  to  Lodingen  on 
Hindo,  just  where  the  culminating  masses  of  the  Kjolen 
Mountains  must  have  poured  their  greatest  glaciers  into  the 
sea  by  a  westward  course,  and  these  glaciers  must  have  been 
met  by  another  stream  pouring  from  the  north,  formed  by 
the  glaciers  of  HindO  and  Senjeno,  and  both  must  have 
coalesced  with  a  third  flood  pouring  through  the  Ofoten 
fjord,  the  Tys  fjord,  etc.,  from  the  mainland.  The  Vest 
fjord  is  about  sixty  miles  wide  at  its  mouth,  and  narrows 
northward  till  it  terminates  in  the  Ofoten  fjord,  which  forks 


THE  "GREAT  ICE  AGE."  131 

into  several  branches  eastward.  A  glance  at  a  good  map 
will  show  that  here,  according  to  my  explanation  of  the  origin 
of  the  till,  there  should  be  the  greatest  of  all  the  submarine 
plains  of  till  which  the  ancient  Scandinavian  glaciers  have 
produced,  and  of  which  the  plains  of  till  I  saw  on  the  coast 
at  Bodo  (which  lies  just  to  the  mouth  of  the  Vest  fjord, 
where  the  Salten  fjord  flows  into  it),  are  but  the  slightly 
inclined  continuation. 

Some  idea  of  this  bank  may  be  formed  from  the  fact  that 
outside  of  the  Lofodens  the  sea  is  100  to  200  fathoms  in 
depth,  that  it  suddenly  shoals  up  to  16  or  20  fathoms  on 
the  east  side  of  these  rocks,  and  this  shallow  plain  extends 
across  the  whole  50  or  60  miles  between  these  islands  and 
the  mainland.*  It  must  not  be  supposed  the  fjords  or  inlets 
of  Scandinavia  are  usually  shallower  than  the  open  sea;  the 
contrary  is  commonly  the  case,  especially  with  the  norrowest 
and  those  which  run  farthest  inland.  They  are  very  much 
deeper  than  the  open  sea. 

If  space  permitted  I  could  show  that  the  great  Storregen 
bank,  opposite  Aalesund  and  Molde,  where  the  Stor  fjord, 
Mold  fjord,  etc.,  were  the  former  outlets  of  the  glaciers 
from  the  highest  of  all  the  Scandinavian  mountains,  and  the 
several  banks  of  Fiumark,  etc.,  from  which,  in  the  aggre- 
gate, are  taken  another  20  or  30  millions  of  cod-fish  annu- 
ally, are  all  situated  just  where  theoretically  they  ought  to 
be  found.  The  same  is  the  case  with  the  great  bank  of 
Newfoundland  and  the  banks  around  Iceland,  which  are 

*  The  celebrated  "  MaelstrOm"  is  one  of  the  currents  that  flow  down 
the  submarine  incline  between  these  islands  when  the  tide  is  falling. 
Although  I  have  ridiculed  some  of  the  accounts  of  this  now  innocent 
stream,  I  am  not  prepared  to  assert  that  it  was  always  as  mild  as  at 
present.  If  the  ancient  glaciers  were  stopped  suddenly,  as  they'may 
well  have  been,  by  the  rocky  barrier  of  Mosken,  between  Vaero  and 
Moskeneso,  and  they  then  suddenly  concluded  their  deposition  of  till, 
a  precipice  must  have  been  formed  between  this  and  the  deep  sea  out- 
side the  islands,  down  which  the  sea  would  pitch  when  the  tide  was 
falling,  and  thus  form  some  dangerous  eddies.  This  cascade  would 
gradually  obliterate  itself  by  wearing  down  the  precipitous  wall  to  an 
inclined  plane  such  as  at  present  exists,  and  down  which  the  existing 
current  flows. 


132  SCIENCE  IN  SHORT  CHAPTERS. 

annually  visited  by  large  numbers  of  French  fishermen 
from  Dunkerque,  Boulogne,  and  other  ports. 

Whenever  the  packet  halted  over  these  banks  during  our 
coasting  trip  we  demonstrated  their  fertility  by  casting  a  line 
or  two  over  the  bulwark.  No  bait  was  required,  merely  a 
double  hook  with  a  flat  shank  attached  to  a  heavy  leaden 
plummet.  The  line  was  sunk  till  the  lead  touched  the 
bottom,  a  few  jerks  were  given,  and  then  a  tug  was  felt:  the 
line  was  hauled  in  with  a  cod-fish  or  hallibut  hooked,  not 
inside  the  mouth,  but  externally  by  the  gill-plates,  the  back, 
the  tail,  or  otherwise.  The  mere  jerking  of  a  hook  near  the 
bottom  was  sufficient  to  bring  it  in  contact  with  some  of  the 
population.  There  is  a  very  prolific  bank  lying  between 
the  North  Cape  and  Nordkyn,  where  the  Porsanger  and  Laxe 
fjords  unite  their  openings.  Here  we  were  able,  with  only 
three  lines,  to  cover  the  fore-deck  of  the  packet  with  strug- 
gling victims  in  the  course  of  short  halts  of  fifteen  to  thirty 
minutes.  Not  having  any  sounding  apparatus  by  which 
to  fairly  test  the  nature  of  the  sea-bottom  in  these  places, 
I  cannot  offer  any  direct  proof  that  it  was  composed  of  till. 
By  dropping  the  lead  I  could  feel  it  sufficiently  to  be  cer- 
tain that  it  was  not  rock  in  any  case,  but  a  soft  deposit, 
and  the  marks  upon  the  bottom  of  the  lead,  so  far  as  they 
went,  afforded  evidence  in  favor  of  its  clayey  character.  A 
further  investigation  of  this  would  be  very  interesting. 

But  the  most  striking — I  may  say  astounding — evidence 
of  the  fertility  of  these  banks,  one  which  appeals  most 
powerfully  to  the  senses,  is  the  marvelous  colony  of  sea- 
birds  at  Sverholtklubben,  the  headland  between  the  two 
last-named  fjords.  I  dare  not  estimate  the  numbers  that 
rose  from  the  rocks  and  darkened  the  sky  when  we  blew 
the. steam- whistle  in  passing.  I  doubt  whether  there  is  any 
other  spot  in  the  world  where  an  equal  amount  of  animal 
life  is  permanently  concentrated.  All  these  feed  on  fish, 
and  an  examination  of  the  map  will  show  why — in  accord- 
ance with  the  above  speculations — they  should  have  chosen 
Sverholtklubben  as  the  best  fishing-ground  on  the  arctic 
face  of  Europe. 

I  am  fully  conscious  of  the  main  difficulty  that  stands  in 
the  way  of  my  explanation  of  the  formation  of  the  till,  viz., 


THE  "GREAT  ICE  AGE."  183 

that  of  finding  sufficient  water  to  float  the  ice,  and  should 
have  given  it  up  had  I  accepted  Mr.  Geikie's  estimate  of 
the  thickness  of  the  great  ice-sheet  of  the  great  ice  age. 

He  says  (page  186)  that  "The  ice  which  covered  the  low 
grounds  of  Scotland  during  the  early  cold  stages  of  the 
glacial  epoch  was  certainly  more  than  2000  feet  in  thick- 
ness, and  it  must  have  been  even  deeper  than  this  between 
the  mainland  and  the  Outer  Hebrides.  To  cause  such  a 
mass  to  float,  the  sea  around  Scotland  would  require  to  be- 
come deeper  than  now  by  1400  or  1500  feet  at  least." 

I  am  unable  to  understand  by  what  means  Mr.  Geikie 
measured  this  depth  of  the  ice  which  covered  these  low 
grounds,  except  by  assuming  that  its  surface  was  level  with 
that  of  the  upper  ice-marks  of  the  hills  beyond.  The  fol- 
lowing passage  on  page  63  seems  to  indicate  that  he  really 
has  measured  it  thus: — 

"  Now  the  scratches  may  be  traced  from  the  islands  and 
the  coast-line  up  to  an  elevation  of  at  least  3,500  feet;  so 
that  ice  must  have  covered  the  country  to  that  height  at 
least.  In  the  Highlands  the  tide  of  ice  streamed  out  from 
the  central  elevations  down  all  the  main  straths  and  glens; 
and  by  measuring  the  height  attained  by  the  smoothed  and 
rounded  rocks  we  are  enabled  to  estimate  roughly  the  prob- 
able thickness  of  the  old  ice-sheet.  But  it  can  only  be  a 
rough  estimate,  for  so  long  a  time  has  elapsed  since  the  ice 
disappeared,  the  rain  and  frost  together  have  so  split  up 
and  worn  down  the  rocks  of  these  highland  mountains 
that  much  of  the  smoothing  and  polishing  has  vanished. 
But  although  the  finer  marks  of  the  ice-chisel  have  thus 
frequently  been  obliterated,  yet  the  broader  effects  remain 
conspicuous  enough.  From  an  extensive  examination  of 
these  we  gather  that  the  ice  could  not  have  been  less,  and 
was  probably  more  than  3,000  feet  thick  in  its  deepest 
parts." 

Page  80  he  says:  "  Bearing  in  mind  the  vast  thickness 
reached  by  the  Scotch  ice-sheet,  it  becomes  very  evident 
that  the  ice  would  flow  along  the  bottom  of  the  sea  with  as 
much  ease  as  it  poured  across  the  land,  and  every  island 
would  be  surmounted  and  crushed,  and  scored  and  polished 
just  as  readily  as  the  hills  of  the  mainland  were." 


134  SCIENCE  IN  SHORT  CHAPTERS. 

Mr.  Geikie  describes  the  Scandinavian  ice-sheet  in  simi- 
lar terms,  but  ascribes  to  it  a  still  greater  thickness.  He 
says  (page  404) — "  The  whole  country  has  been  moulded 
and  rubbed  and  polished  by  an  immense  sheet  of  ice,  which 
could  hardly  have  been  less  than  6,000  or  even  7,000  feat 
thick,"  and  he  maintains  that  this  spread  over  the  sea  and 
coalesced  with  the  ice-sheet  of  Scotland. 

My  recollection  of  the  Lof oden  Islands,  which  from  their 
position  afford  an  excellent  crucial  test  of  this  question,  led 
me  to  believe  that  their  configuration  presented  a  direct 
refutation  of  Mr.  Geikie's  remarkable  inference:  but  a  mere 
recollection  of  scenery  being  too  vague,  a  second  visit  was 
especially  desirable  in  reference  to  this  point.  The  result 
of  the  special  observations  I  made  during  this  second  visit 
fully  confirmed  the  impression  derived  from  memory. 

I  found  in  the  first  place  that  all  along  the  coast  from 
Stavanger  to  the  Varanger  fjord  every  rock  near  the  shore 
is  glaciated;  among  the  thousands  of  low-lying  ridges  that 
peer  above  the  water  to  various  heights  none  near  the  main- 
land are  angular.  The  general  character  of  these  is  shown 
in  the  sketch  of  "  My  Sea  Serpent,"  in  the  last  edition  of 
"  Through  Norway  with  a  Knapsack." 

The  rocks  which  constitute  the  extreme  outlying  limits 
of  the  Lofoden  group,  and  which  are  between  60  and  70 
miles  from  the  shore,  although  mineralogically  correspond- 
ing with  those  near  the  shore,  are  totally  different  in  their 
conformation,  as  the  sketch  of  three  characteristic  speci- 
mens plainly  shows.  Mr.  Everest  very  aptly  compares 
them  to  shark's  teeth.  Proceeding  northward,  these  rocks 
gradually  progress  in  magnitude,  until  they  become  moun- 
tains of  3,000  to  4,000  feet  in  height;  their  outspread 
bases  form  large  islands,  and  the  Vest  fjord  gradually  nar- 
rows. 

The  remarkably  angular  and  jagged  character  of  these 
rocks  when  weathered  in  the  air  renders  it  very  easy  to 
trace  the  limits  of  glaciation  on  viewing  them  at  a  distance. 
The  outermost  and  smallest  rocks  show  from  a  distance  no 
signs  of  glaciation.  If  submerged,  the  ice  of  the  great  ice 
age  was  then  enough  to  float  over  without  touching  them; 
if  they  stood  above  the  sea,  as  at  present,  they  suffered  no 


THE  "  GREAT  ICE  AGE."  135 

more  glaciation  than  would  be  produced  by  sucli  an  ice- 
sheet  as  that  of  the  "  paleocrystic  "  ice  recently  found  by 
Captain  Nares  on  the  north  of  Greenland.  Progressing 
northward,  the  glaciatiou  begins  to  become  visible,  running 
up  to  about  100  feet  above  the  sea-level  on  the  islands  lying 
westward  and  southward  of  Ost  Vaagen.  Further  north- 
ward along  the  coast  of  Ost  Vaagen  and  Hindo,  the  level 
gradually  rises  to  about  500  feet  on  the  northern  portion  of 
Ost  Vaagen,  and  up  to  more  than  1,000  feet  on  Hindo, 
while  on  the  mainland  it  reaches  3,000  to  4,000  feet. 

A  remarkable  case  of  such  variation,  or  descent  of  ice- 
level,  as  the  ice-sheet  proceeded  seaward,  is  shown  at 
Tromso.  This  small  oblong  island  (lat.  69°  40'),  on  which 
is  the  capital  town  of  Finmark,  lies  between  the  mainland 
and  the  large  mountainous  island  of  Kvalo,  with  a  long 
sea-channel  on  each  side,  the  Tromosund  and  the  Sande- 
sund;  the  total  width  of  these  two  channels  and  the  island 
itself  being  about  four  or  five  miles.  The  general  line  of 
glaciation  from  the  mainland  crosses  the  broad  side  of  these 
channels  and  the  island,  which  has  evidently  been  buried 
and  ground  down  to  its  present  moderate  height  of  two  or 
three  hundred  feet.  Both  of  the  channels  are  till  paved. 
On  the  east  or  inland  side  the  mountains  near  the  coast  are 
glaciated  to  their  summits — are  simply  roches  moutonnees, 
over  which  the  reindeer  of  the  Tromsdal  Lapps  range  and 
feed.  On  the  west  the  mountains  are  dark,  pyramidal, 
non-glaciated  peaks,  with  long  vertical  snow-streaks  mark- 
ing their  angular  masses. 

The  contrast  is  very  striking  when  seen  from  the  highest 
part  of  the  island,  and  is  clearly  due  to  a  decline  in  the 
thickness  of  the  ice-sheet  in  the  course  of  its  journey  across 
this  narrow  channel.  Speaking  roughly  from  my  estima- 
tion, I  should  say  that  this  thinning  or  lowering  of  the  lim- 
its of  glaciation  exceeds  500  feet  between  the  opposite  sides 
of  the  channel,  which,  allowing  for  the  hill  slopes,  is  a  dis- 
tance of  about  6  miles.  This  very  small  inclination  would 
bring  a  glacier  of  3,000  feet  in  thickness  on  the  shore  down 
to  the  sea-level  in  an  outward  course  of  30  miles,  or  about 
half  the  distance  between  the  mainland  and  the  outer  rocks 
of  the  Lofodens  shown  in  the  engraving. 


136  SCIENCE  IN  SHORT  CHAPTERS. 

I  am  quite  at  a  loss  to  understand  the  reasoning  upon 
which.  Mr.  Geikie  bases  his  firm  conviction  respecting  the 
depth  of  the  ice-sheet  on  the  low  grounds  of  Scotland  and 
Scandinavia.  He  seems  to  assume  that  the  glaciers  of  the 
great  ice  age  had  little  or  no  superficial  down  slope  corre- 
sponding to  the  inclination  of  the  base  on  which  they  rested. 
I  have  considerable  hesitation  in  attributing  this  assump- 
tion to  Mr.  Geikie,  and  would  rather  suppose  that  I  have 
misunderstood  him,  as  it  is  a  conclusion  so  completely  re- 
futed by  all  we  know  of  glacier  phenomena  and  the  physi- 
cal laws  concerned  in  their  production;  but  the  passages  I 
have  quoted,  and  several  others,  are  explicit  and  decided. 

Those  geologists  who  contend  for  the  former  existence 
of  a  great  polar  ice-cap  radiating  outwards  and  spreading 
into  the  temperate  zones,  might  adopt  this  mode  of  measur- 
ing its  thickness,  but  Mr.  Geikie  rejects  this  hypothesis, 
and  shows  by  his  map  of  "  The  Principal  Lines  of  Glacial 
Erosion  in  Sweden,  Norway,  and  Finland,"  that  the  glacia- 
tiou  of  the  extreme  north  of  Europe  proceeded  from  south 
to  north;  that  the  ice  was  formed  on  land,  and  proceeded 
seawards  in  all  directions. 

I  may  add  to  this  testimony  that  presented  by  the  North 
Cape,  Sverholt,  Nordkyn,  and  the  rest  of  the  magnificent 
precipitous  headlands  that  constitute  the  characteristic  fea- 
ture of  the  arctic-face  of  Europe.  They  stand  forth  de- 
fiantly as  a  phalanx  of  giant  heralds  proclaiming  aloud  the 
fallacy  of  this  idea  of  southward  glacial  radiation;  and  in 
concurrence  with  the  structure  and  striation  of  the  great 
glacier  troughs  that  lie  between  them,  and  the  planed  table- 
land at  their  summits,  they  establish  the  fact  that  during 
the  greatest  glaciation  of  the  glacial  epoch  the  ice-streams 
were  formed  on  land  and  flowed  out  to  sea,  just  as  they 
now  do  at  Greenland,  or  other  parts  of  the  world  where  the 
snow  line  touches  or  nearly  approaches  the  level  of  the  sea. 

All  such  streams  must  have  followed  the  slope  of  the 
hill-sides  upon  which  they  rested  and  down  which  they 
flowed,  and  thus  the  upper  limits  of  glaciation  afford  no 
measure  whatever  of  the  thickness  of  "the  ice  upon  "the 
low  grounds  of  Scotland,"  or  of  any  other  glaciated  country. 
As  an  example,  I  may  refer  to  Mont  Blanc.  In  climbing 


THE  "GREAT  1HE  AdE''  137 

this  mountain  the  journey  from  the  lower  ice-wall  of  the 
Glacier  de  Bessons  up  to  the  bergschrund  above  the  Grand 
Plateau  is  over  one  continuous  ice-field,  the  level  of  the 
upper  part  of  which  is  more  than  10,000  feet  above  its  ter- 
minal ice-wall.  Thus,  if  we  take  the  height  of  the  stria- 
ations  or  smoothings  of  the  upper  neve  above  the  low 
grounds  on  which  the  ice-sheet  rests,  and  adopt  Mr.  Geikie's 
reasoning,  the  lower  ice- wall,  of  the  Glacier  de  Bessons 
should  be  10,000  feet  thick.  Its  actual  thickness,  as  nearly 
as  I  can  remember,  is  about  10.  or  12  feet. 

Every  other  known  glacier  presents  the  same  testimony. 
The  drawing  of  a  Greenland  glacier  opposite  page  47  of 
Mr.  Geikie's  book  shows  the  same  under  arctic  conditions, 
and  where  the  ice- wall  terminates  in  the  sea. 

I  have  not  visited  the  Hebrides,  but  the  curious  analogy 
of  their  position  to  that  of  the  Lofodens  suggests  the  de- 
sirability of  similar  observations  to  those  I  have  made  in 
the  latter.  If  the  ice  between  the  mainland  and  the  Outer 
Hebrides  was,  as  Mr.  Geikie  maintains,  "certainly  more 
than  2000  feet  in  thickness,"  and  this  stretched  across  to 
Ireland,  besides  uniting  with  the  still  thicker  ice-sheet  of 
Scandanavia,  these  islands  should  all  be  glaciated,  especially 
the  smaller  rocks.  If  I  am  right,  the  smaller  outlying 
islands,  those  south  of  Barra,  should,  like  the  corresponding 
rocks  of  the  Lofodens,  display  no  evidence  of  having  been 
overswept  by  a  deep  "mer  de  glace." 

I  admit  the  probability  of  an  ice-sheet  extending  as  Mr. 
Geikie  describes,  but  maintain  that  it  thinned  out  rapidly 
seaward,  and  there  became  a  mere  ice-floe,  such  as  now  im- 
pedes the  navigation  of  Smith's  Sound  and  other  portions 
of  the  Arctic  Ocean.  The  Orkneys  and  Shetlands,  with 
which  I  am  also  unacquainted,  must  afford  similar  crucial 
instances,  always  taking  into  account  the  fact  that  the 
larger  islands  may  have  been  independently  glaciated  by  the 
accumulations  due  to  their  own  glacial  resources.  It  is  the 
small  rocks  standing  at  considerable  distance  from  the 
shores  of  larger  masses  of  land  that  supply  the  required 
test-conditions. 

From  the  above  it  will  be  seen  that  I  agree  with  Mr. 
Geikie  in  regarding  the  till  as  a  "moraine  profonde,"  but 


138  SCIENCE  IN  SHORT  CHAPTERS. 

differ  as  to  the  mode  and  place  of  its  deposition."  He 
argues  that  it  was  formed  under  glaciers  of  the  thickness  he 
describes,  while  their  whole  weight  rested  upon  it. 

This  appears  to  me  to  be  physically  impossible.  If  such 
glaciers  are  capable  of  eroding  solid  rocks,  the  slimy  mud  of 
their  own  deposits  could  not  possibly  have  resisted  them. 
The  only  case  where  this  might  have  happened  is  where  a 
mountain-wall  has  blocked  the  further  downward  progress 
of  a  glacier,  or  in  pockets,  or  steep  hollows  which  a  glacier 
might  have  bridged  over  aud  filled  up;  but  such  pockets 
are  by  no  means  the  characteristic  localities  of  till,  though 
the  till  of  Switzerland  may  possibly  show  examples  of  the 
first  case.  The  great  depth  of  the  inland  lakes  of  Norway, 
their  bottoms  being  usually  far  below  that  of  the  present 
sea-bottom,  is  in  direct  contradiction  of  this.  *  They  should, 
before  all  places,  be  filled  with  till,  if  the  tillVere  a  ground 
moraine  formed  on  land;  but  all  we  know  of  them  confirms 
the  belief  that  the  glaciers  deepened  them  by  erosion  instead 
of  shallowing  them  by  deposition. 

Mr.  Geikie's  able  defence  of  Ramsay's  theory  of  lake- 
basin  erosion  is  curiously  inconsistent  with  his  arguments  in 
favor  of  the  ground  moraine. 

I  fully  concur  with  Mr.  Geikie's  arguments  against  the 
iceberg  theory  of  the  formation  of  the  till.  This,  I  think, 
he  has  completely  refuted. 

Before  concluding  I  must  say  a  few  words  on  those  curi- 
ous lenticular  beds  of  sand  and  gravel  in  the  till  which  ap- 
pear so  very  puzzling.  A  simple  explanation  is  suggested 
in  connection  with  the  above-sketched  view  of  the  forma- 
tion of  the  till.  All  glaciers,  whether  in  arctic  or  temperate 
climates,  are  washed  by  streamlets  during  summer,  and 
these  commonly  terminate  in  the  form  of  a  stream  or  cas- 

*  The  largest  of  the  Norwegian  lakes,  the  Mjosen,  is  1550  feet  deep, 
and  its  surface  385  feet  above  the  sea-level.  Its  bottom  is  about  1000 
feet  lower  than  the  sea  outside,  or  500  to  800  feet  below  the  bottom 
of  the  Christiana  Fjord.  The  fjords,  generally  speaking,  are  very 
much  shallower  near  their  mouths  than  further  inland,  as  though 
their  depth  had  been  determined  by  the  thickness  of  the  glaciers 
flowing  down  them,  and  the  consequent  limits  of  flotation  and  de- 
position. 


THE  "  GREAT  ICE  AGE."  139 

cade  pouring  down  a  "  moulin" — a  well  bored  by  themselves 
and  reaching  the  bottom  of  the  glacier.  Now  what  must 
be  the  action  of  such  a  downflow  of  water  upon  my  sup- 
posed submarine  bed  of  till  just  grazing  the  bottom  of  the 
glacier?  Obviously,  to  wash  away  the  fine  clayey  particles, 
and  leave  behind  the  coarser  sand  or  gravel.  It  must  form 
jusfc  such  a  basin  or  lenticular  cavity  as  Mr.  Geikie  de- 
scribes. The  oblong  shape  of  these,  their  longer  axis  co- 
inciding with  the  general  course  of  the  glacier,  would  be 
produced  by  the  onward  progress  of  the  moulin.  The  ac- 
cordance of  their  other  features  with  this  explanation  will 
be  seen  on  reading  Mr.  Geikie's  description  (pp.  18,  19, 
etc). 

The  general  absence  of  marine  animals  and  their  occa- 
sional exceptional  occurrence  in  the  intercalated  beds  is 
just  what  might  be  expected  under  the  conditions  I  have 
sketched.  In  the  gloomy  subglacial  depths  of  the  sea, 
drenched  with  continual  supplies  of  fresh  water  and  cooled 
below  the  freezing-point  by  the  action  of  salt  water  on  the 
ice,  ordinary  marine  life  would  be  impossible;  while,  on  the 
other  hand,  any  recession  of  the  glacial  limit  would  restore 
the  conditions  of  arctic  animal  life,  to  be  again  obliterated 
with  the  renewed  outward  growth  of  the  floating  skirts  of 
the  inland  ice-mantle. 

But  I  must  now  refrain  from  the  further  discussion  of 
these  and  other  collateral  details,  but  hope  to  return  to 
them  in  another  paper. 

In  "Through  Norway  with  Ladies"  I  have  touched 
lightly  upon  some  of  these,  and  have  more  particularly  de- 
scribed some  curious  and  very  extensive  evidences  of  sec- 
ondary glaciation  that  quite  escaped  my  attention  on  my 
first  visit,  and  which,  too,  have  been  equally  overlooked  by 
other  observers.  In  the  above  I  have  endeavored  to  keep 
as  nearly  as  possible  to  the  main  subject  of  the  origin  of  the 
till  and  the  character  of  the  ancient  ice-sheet. 


140  SCIENCE  J.Y  SHORT  CHAPTERS. 


THE  BAROMETER  AND  THE  WEATHER. 

THE  barometer  was  invented  by  Torricelli,  an  Italian 
philosopher  of  the  seventeenth  century.  It  consists  essen- 
tially of  a  long  tube  open  atone  end  and  closed' at  the 
other,  and  partly  filled  with  mercury;  but  instead  of  being 
filled  like  ordinary  vessels,  with  the  open  end  or  mouth  up- 
wards and  the  closed  end  or  bottom  downwards,  the  bar- 
ometer-tube is  inverted,  and  has  its  open  mouth  down- 
wards. This  open  mouth  is  either  dipped  into  a  little  cup 
of  mercury  or  bent  a  little  upwards. 

Why  does  not  the  mercury  run  out  of  this  lower  open  end 
and  overflow  the  little  cup  when  it  is  inverted  after  being 
filled? 

The  answer  to  this  question  includes  the  whole  mystery 
and  principle  of  the  barometer.  The  mercury  does  not  fall 
down  because  something  pushes  it  up  and  supports  it  with 
a  certain  degree  of  pressure,  and  that  something  is  the  at- 
mosphere which  extends  all  round  the  world,  and  presses 
downwards  and  sideways  and  upwards — in  every  direction, 
in  fact — with  a  force'  equal  to  its  weight,  i.  e . ,  witli  a  pres- 
sure equal  to  about  15  Ibs.  on  every  square  inch.  A  column 
or  perpendicular  square  stick  of  air  one  inch  thick  each 
way,-  and  extending  from  the  surface  of  the  sea  up  to  the 
top  of  the  atmosphere,  weighs  about  15  Ibs.;  other  columns 
or  sticks  next  to  it  on  all  sides  weigh  the  same,  and  so  on 
with  every  portion;  and  all  these  are  for  ever  squeezing 
down  and  against  each  other,  and,  being  fluid,  transmit 
their  pressure  in  every  direction,  and  against  the  earth  and 
everything  upon  it,  and  therefore  upon  the  mercury  of  the 
barometer-tube. 

We  have  supposed  the  air  to  be  made  up  of  columns  or 
sticks  of  air  one  inch  each  way,  but  might  have  taken  any 
other  size,  and  the  weight  and  pressure  would  be  propor- 
tionate. Now  mercury,  bulk  for  bulk,  is  so  much  heavier 
than  air,  that  a  stick  or  column  of  this  liquid  metal  about 
30  inches  high  weighs  as  much  as  a  stick  or  column  of  air 
of  same  thickness  reaching  from  the  surface  of  the  earth  to 
the  top  of  the  atmosphere;  therefore,  the  30-inch  stick  of 


THE  BAROMETER  AND  THE  WEATHER.    141 

mercury  balances  the  pressure  of  the  many  miles  of  atmos- 
phere, and  is  supported  by  it.  Thus  the  column  of  mer- 
cury may  be  used  to  counterbalance  the  atmosphere  and 
show  us  its  weight;  and  such  a  column  of  mercury  is  a 
barometer,  or  "weight  measure."  The  word  barometer  is 
compounded  of  the  two  Greek  words — laros,  weight,  and 
metron,  a  measure. 

If  you  take  a  glass  tube  a  yard  long,  stopped  at  one 
end  and  open  at  the  other,  fill  it  with  mercury,  stop  the 
open  end  with  your  thumb,  then  invert  the  tube  and  just 
dip  the  open  end  in  a  little  cup  of  mercury,  some  of  the 
mercury  in  the  tube  will  fall  into  the  cup,  but  not  all;  only 
six  inches  will  fall,  the  other  30  inches  will  remain,  with 
an  empty  space  between  it  and  the  stopped  end  of  the  tube. 
When  you  have  done  this  you  will  have  made  a  rude  bar- 
ometer. If  you  prop  up  the  tube,  and  watch  it  carefully 
from  day  to  day,  you  will  find  that  the  height  of  the  column 
of  mercury  will  continually  vary.  If  you  live  at  the  sea- 
level,  or  thereabouts,  it  will  sometimes  rise  more  than  30 
inches  above  the  level  of  the  mercury  in  the  cup,  and  fre- 
quently fall  below  that  height.  If  you  live  on  the  top  of  a 
high  mountain,  or  on  any  high  ground,  it  will  never  reach 
30  inches,  will  still  be  variable,  its  average  height  less  than 
if  you  lived  on  lower  ground;  and  the  higher  you  go  the 
less  will  be  this  average  height  of  the  mercury. 

The  reason  of  this  is  easily  understood.  When  we  ascend 
a  mountain  we  leave  some  portion  of  the  atmosphere  below 
us,  and  of  course  less  remains  above;  this  smaller  quantity 
must  have  less  weight  and  press  the  mercury  less  forcibly. 
If  the  barometer  tells  the  truth,  it  must  show  this  differ- 
ence; and  it  does  so  with  such  accuracy  that  by  means  of 
a  barometer,  or  rather  of  two  barometerg— one  at  the  foot 
of  the  mountain  and  one  at  its  summit — we  may,  by  their 
difference,  measure  the  height  of  the  mountain  provided 
we  know  the  rules  for  making  the  requisite  calculations. 

The  old-fashioned  barometer,  with  a  large  dial-face  and 
hands  like  a  clock,  is  called  the  "wheel  barometer,"  be- 
cause the  mercury,  in  rising  and  falling,  moves  a  little  glass 
float  resting  upon  the  mercury  of  the  open  bent  end  of  the 
tube;  to  this  float  and  its  counterpoise  a  fine  cord  is  attached; 


142  SCIENCE  IN  SHORT  CHAPTERS. 

and  this  cord  goes  round  a  little  grooved  wheel  to  which 
the  hands  are  attached.  Thus  the  rising  and  falling  of  the 
mercury  moves  the  float,  the  float-cord  turns  the  wheel,  and 
the  wheel  moves  the  hands  that  points  to  the  words  and 
figures  on  the  dial.  When  this  hand  moves  towards  the 
right,  or  in  the  direction  of  an  advancing  clock-hand,  the 
barometer  is  rising;  when  it  goes  backwards,  or  opposite  to 
the  clock-hand  movement,  the  mercury  is  falling.  By  open- 
ing the  little  door  at  the  back  of  such  a  barometer,  the 
above-described  mechanism  is  seen.  In  doing  this,  or 
otherwise  moving  your  barometer,  be  careful  always  to 
keep  it  upright. 

It  sometimes  happens  to  these  wheel .  barometers  that 
they. suddenly  cease  to  act;  and  in  most  cases  the  owner  of 
the  barometer  may  save  the  trouble  and  expense  of  sending 
it  to  the  optican  by  observing  whether  the  cord  has  slipped 
from  the  little  wheel,  and  if  so,  simply  replacing  it  in  the 
groove  upon  its  edge.  If,  however,  the  mischief  is  caused 
by  the  tube  being  broken,  which  is  seen  at  once  by  the 
mercury  having  run  out,  the  case  is  serious,  and  demands 
professional  aid. 

The  upright  barometer,  which  shows  the  surface  of  the 
mercury  itself,  is  the  most  accurate  instrument,  provided 
it  is  carefully  read.  This  form  of  instrument  is  always 
used  in  meteorological  observatories,  where  minute  correc- 
tions are  made  for  the  expansion  and  contraction  which 
variations  of  temperature  produce  upon  the  length  of  the 
mercury  without  altering  its  weight,  and  for  the  small 
fluctuations  in  the  level  of  the  mercury  cistern.  With 
such  instruments,  fitted  with  an  apparatus  called  a  "ver- 
nier" the  height  of  the  mercury  may  be  read  to  hundredth^ 
of  an  inch. 

The  necessity  for  the  30  inches  of  mercury  renders  the 
mercurial  barometer  a  rather  cumbrous  instrument:  it  must 
be  more  than  30  inches  long,  and  is  liable  to  derangement 
from  the  spilling  of  the  mercury.  On  this  account  port- 
able barometers  of  totally  different  construction  have  been 
invented.  The  "aneroid"  barometer  is  one  of  these — the 
only  one  that  is  practically  used  to  any  extent.  It  contains 
a  metal  box  partly  filled  with  air;  one  face  of  the  box  is 


THE  BAROMETER  AND  THE   WEATHER.        143 

corrugated,  and  so  thin  that  it  can  rise  and  fall  like  a 
stretched  covering  of  india-rubber.  As  the  pressure  of  the 
outside  air  varies  it  does  rise  and  fall,  and  by  a  beautifully- 
delicate  apparatus  this  rising  and  falling  is  magnified  and 
represented  upon  the  dial.  Such  barometers  are  made  small 
enough  to  be  carried  in  the  pocket,  and  are  very  useful  for 
measuring  the  heights  of  mountains;  but  they  are  not  quite 
so  accurate  as  the  mercurial  barometer,  and  are  therefore 
net  used  for  rigidly  scientific  measurements;  but  for  all 
ordinary  purposes  they  are  accurate  enough,  provided  they 
are  occasionally  compared  with  a  standard  mercurial  bar- 
ometer, and  adjusted  by  means  of  a  watch-key  axis  pro- 
vided for  that  purpose,  and  seen  on  the  back  of  the  instru- 
ment. They  are  sufficiently  delicate  to  tell  the  traveller  in 
a  railway  whether  he  is  ascending  or  descending  an  incline, 
and  will  indicate  the  difference  01  height  between  the  upper 
ai>d  lower  rooms  of  a  three-story  house.  With  due  allow- 
ance for  variations  of  level,  the  traveler  may  use  them  as 
weather  indicators;  especially  as  it  is  the  direction  in  which 
the  barometer  is  moving  (whether  rising  or  falling)  rather 
than  its  absolute  height  that  indicates  changes  of  weather. 
Thus  by  placing  the  aneroid  in  his  room  on  reaching  his 
hotel  at  night,  carefully  marking  its  height  then  and  there, 
and  comparing  this  with  another  observation  made  on  the 
following  morning,  he  may  use  it  as  a  weather-glass  in  spite 
of  hill  and  dale. 

Water  barometers  have  been  made  on  the  same  principle 
as  the  mercury  barometer;  but  as  water  is  13£  times 
lighter,  bulk  for  bulk,  than  mercury,  the  height  of  the 
column  must  be  13£  times  30  inches,  or,  allowing  for  vari- 
ations, not  less  than  34  feet.  This,  of  course,  is  very 
cumbrous;  the  evaporation  of  the  water  presents  another 
considerable  difficulty,*  still  such  a  barometer  is  a  very  in- 
teresting instrument,  as  it  shows,  the  atmospheric  fluctua- 
tions on  13£  times  the  scale  of  the  ordinary  barometer. 
A  range  of  about  five  feet  is  thus  obtained;  and  not  only 


*  This  has  been  recently  overcome  to  a  great  extent  by  using  gly- 
cerine instead  of  water. 


144  SCIENCE  IN  SHORT  CHAPTERS. 

the  great  waves,  but  even  the  comparatively  small  ripples 
of  the  atmospheric  ocean  are  displayed  by  it.  In  stormy 
weather  it  may  be  seen  to  rise  and  fall  and  pulsate  like  a 
living  creature,  so  sensitively  does  it  respond  to  every  at- 
mospheric fluctuation. 

But  why  should  the  height  of  the  barometer  vary  white 
it  remains  in  the  same  place? 

If  the  quantity  of  air  surrounding  the  earth  remains  ihe 
same,  and  if  the  barometer  measures  its  weight  correctly, 
why  should  the  barometer  vary? 

Does  the  atmosphere  grow  bigger  and  smaller,  lighter 
and  heavier,  from  time  to  time? 

These  are  fair  questions,  and  they  bring  us  at  once  to 
some  of  the  chief  uses  of  the  barometer.  The  atmosphere 
is  a  great  gaseous  ocean  surrounding  the  earth,  and  MX-  sre 
creeping  about  on  the  bottom  of  this  ocean.  It  has  its 
tides  and  billows  and  whirling  eddies,  but  all  these  are 
vastly  greater  than  those  of  the  watery  ocean.  At  ane 
time  we  are  under  the  crest  or  rounded  portion  of  a  mighty 
atmospheric  wave,  at  another  the  hollow  between  two  such 
waves  is  over  our  heads,  and  thus  the  depth  of  atmosphere, 
or  quantity  of  air,  above  us  is  variable.  This  variation  is 
the  combined  result  of  many  co-operating  causes.  In  the 
first  place,  there  are  great  atmospheric  tides,  caused,  like 
those  of  the  sea,  by  the  attraction  of  the  sun  and  moon; 
but  these  do  not  directly  affect  the  barometer,  because  the 
attracting  body  supports  whatever  it  lifts.  Variations  of 
temperature  also  produce  important  fluctuations  in  the 
height  and  density  of  the  atmosphere,  some  of  which  are 
indicated  by  the  barometer — others  are  not.  Thus  a  mere 
expansion  or  contraction  of  dry  air,  increasing  the  depth 
or  the  density  of  the  atmospheric  .ocean,  would  not  affect 
the  barometer,  as  mere  expansion  and  contraction  only 
alter  the  bulk  without  affecting  the  weight  of  the  air.  But 
our  atmosphere  consists  not  only  of  the  permanent  gases, 
nitrogen  and  oxygen;  it  contains  besides  these  and  carbonic 
acid,  a  considerable  quantity  of  gaseous  matter,  which  is 
not  permanent,  but  which  may  be  a  gas  at  one  moment — 
contributing  its  whole  weight  to  that  of  the  general  atmos- 
phere— and  at  another  moment  some  of  it  may  be  con- 


THE  BAROMETER  AND   THE   WEATHER.        145 

densed  into  liquid  particles  that  fall  through  it  more  or 
less  rapidly,  and  thus  contribute  nothing  to  its  weight. 

What,  then,  is  this  variable  constituent  that  sometimes 
adds  to  the  weight  of  the  atmosphere  and  the  consequent 
height  of  the  baromerer,  and  at  others  may  suddenly  cease 
to  afford  its  full  contribution  to  atmospheric  pressure? 

It  is  simply  water,  which,  as  we  all  know,  exists  as  solid, 
liquid,  or  gas,  according  to  the  temperature  and  pressure 
to  which  it  is  exposed.  We  all  know  that  steam  when  it 
first  issues  from  the  spout  of  a  tea-kettle  is  a  transparent 
gas,  or  true  vapor,  but  that  presently,  by  contact  with  the 
cool  air,  it  becomes  white,  cloiidy  matter,  or  minute  parti- 
cles of  water;  and  that,  if  these  are  still  further  cooled, 
they  will  become  hoar-frost  or  snow,  or  solid  ice.  Artificial 
hoar-frost  and  snow  may  be  formed  by  throwing  a  jet  of 
steam  into  very  cold,  frosty  air.  If  you  take  a  tin  canister 
qr  other  metal  vessel,  fill  it  with  a  mixture  of  salt  with 
pounded  ice  or  snow,  and  then  hold  the  outside  of  the  can- 
ister against  a  jet  of  steam,  such  as  issues  from  the  spout 
of  a  tea-kettle,  a  snowy  deposit  of  hoar-frost  will  coat  the 
outside  of  the  tin.  Now  let  us  consider  what  takes  place 
when  a  warm  south-westerly  wind,  that  has  swept  over  the 
tropical  regions  of  the  Atlantic  ocean,  reaches  the  compar- 
atively cold  sliores  of  Britain.  It  is  cooled  thereby,  and 
some  of  its  gaseous  water  is  condensed — forming  mists, 
clouds,  rain,  hoar-frost  or  snow.  The  greater  part  of  this 
forms  and  fulls  on  the  western  coasts,  on  Cornwall,  Ire- 
land, the  Western  Highlands  of  Scotland.  Ireland  gets 
the  lion's  share  of  this  humidity,  and  hence  her  "  emerald  " 
verdure.  The  western  slope  of  a  mountain,  in  like  man- 
ner, receives  more  rain  than  the  side  facing  the  east. 

How  does  this  condensation  affect  the  barometer? 

It  must  evidently  cause  it  to  fall,  inasmuch  as  the  air 
must  be  lightened  to  the  exact  extent  of  all  that  is  taken 
out  of  it  and  precipitated.  But  the  precipitation  is  not 
completed  immediately  the  condensation  occurs.  It  takes 
some  time  for  the  minute  cloudy  particles  to  gather  into 
rain  drops  and  fall  to  the  earth,  while  the  effect  of  the  con- 
densation upon  the  barometer  is  instantaneous;  the  air  be- 
gins to  grow  lighter  immediately  the  gas  is  converted  into 


116  SCIENCE  IN  SHORT  CHAPTERS. 

cloud  or  mist,  and  the  barometer  falls  just  at  the  same  time 
and  same  rate  as  this  is  produced;  but  the  rain  comes  some 
time  afterwards.  Hence  the  use  of  the  barometer  as  a 
<•'  weather  glass."  When  intelligently  and  properly  used  it 
is  very  valuable  in  this  capacity;  but,  like  most  things,  it 
may  easily  be  misunderstood  and  misused. 

The  most  common  error  in  the  use  of  the  barometer  is 
that  to  which,  people  are  naturally  led  by  the  words  en- 
graved upon  it,  "Stormy,  Much  Eain,  Rain,  Change, 
Fair,  Set  Fair,"  etc.  A  direct  and  absolute  blunder  or 
falsehood  is  usually  short-lived,  and  deceives  but  few  peo- 
ple; but  a  false  statement,  with  a  certain  amount  of  super- 
ficial truth,  may  survive  for  ages,  and  deceive  whole  gener- 
ations. Now  this  latter  is  just  the  character  of  the  weather 
signs  that  are  engraved  on  our  popular  barometers;  they 
are  unsound  and  deceptive,  but  not  utterly  baseless. 

Stormy,  Much  Rain,  and  Rain  are  marked  against  the 
low  readings  of  the  barometer,  and  Very  Dry,  Set  Fair, 
and  Fair  against  the  higher  readings.  A  low  barometer 
is  not  a  reliable  sign  of  wet  or  stormy  weather,  neither  is  a 
high  barometer  to  be  depended  upon  for  expecting  fine 
weather;  and  yet  it  is  true  that  we  are  more  likely  to  have 
fine  weather  with  a  high  than  with  a  low  barometer,  and 
also  the  liability  to  rain  and  storms  is  greaier  with  a  1  nv 
than  witli  a  high  barometer. 

The  best  indications  of  the  weather  are  those  derived 
from  the  directidn  in  which  the  barometer  is  moving — 
whether  rising  or  falling — rather  than  its  mere  absolute 
height. 

A  sudden  and  considerable  fall  is  an  almost  certain  indi- 
cation of  strong  winds  and  stormy  weather.  This  is  the 
most  reliable  of  the  prophetic  warnings  of  the  barometer, 
and  the  most  useful,  inasmuch  as  it  affords  the  mariner 
just  the  warning  he  requires  when  lying  off  a  dangerous 
coast,  or  otherwise  in  peril  by  a  coming  gale.  Many  a 
good  ship  has  been  saved  by  intelligent  attention  to  the 
barometer,  and  by  running  into  haven,  or  away  from  a. 
rocky  shore  when  the  barometer  has  fallen  with  unusual 
rapidity. 

The  next  in  order  of  reliability  is  the  indication  afforded 


THE  BAROMETER  AND  THE  WEATHER.        147 

by  a  steady  and  continuous  fall  after  a  long  period  of  fine 
weather.  This  is  usually  followed  by  a  decided  change  of 
weather,  and  the  greater  the  fall  the  more  violent  the 
change.  If  the  fall  is  slow,  and  continues  steadily  for  a 
long  time,  the  change  is  likely  to  be  less  sudden  but  more 
permanent,  i.e.,  the  rain  will  probably  arrive  after  some 
time,  and  then  continue  steadily  for  a  long  period. 

In  like  manner,  a  steady,  regular  rise,  going  on  for  some 
days  in  the  midst  of  wet  weather,  may  be  regarded  as  a 
hopeful  indication  of  coming  continuous  fine  weather— :the 
more  gradual  and  steady  the  rise,  the  longer  is  the  fine 
weather  likely  to  last. 

The  least  reliable  of  all  the  barometric  changes  is  a  sud- 
den rise.  In  winter  it  may  be  followed  by  hard  and  sud- 
den frost,  in  summer  by  sultry  weather  and  thunder-storms. 
All  that  may  be  safely  said  of  such  sudden  rise  is,  that  it 
indicates  a  change  of  some  sort. 

The  barometer  is  usually  high  with  N.B.  winds,  and 
low  with  S.W.  winds.  The  preceding  explanations  show 
the  reason  of  this.  In  a  given  place  the  extreme  range  of 
variation  is  from  2  to  2-j  inches. 

It  has  been  proposed  that  the  following  rules  should 
be  engraved  on  barometer  -  plates  instead  of  the  usual 
words : — 

1st.  Generally,  the  rising  of  the  mercury  indicates  the 
approach  of  fair  weather;  the  falling  of  it  shows  the  ap- 
proach of  foul  weather. 

2d.  In  sultry  weather,  the  fall  of  the  barometer  indi- 
cates coming  thunder.  In  winter,  the  rise  of  the  mercury 
indicates  frost.  In  frost,  its  fall  indicates  thaw,  and  its 
rise  indicates  snow. 

3d.  Whatever  change  in  the  weather  suddenly  follows  a 
change  in  the  barometer,  may  be  expected  to  last  but  a 
short  time. 

4th.  If  fair  weather  continues  for  several  days,  during 
which  the  mercury  continually  falls,  a  long  succession  of 
foul  weather  will  probably  ensue;  and  again,  if  foul 
weather  continues  for  several  days,  while  the  mercury  con- 
tinually rises,  a  long  succession  of  fair  weather  will  proba- 
bly follow. 


148  SCIENCE  IN  SHORT  CHAPTERS. 

5th.  A  fluctuating  and  unsettled  state  of  the  mercurial 
column  indicates  changeable  weather. 

As  the  barometer  is  subject  to  slight  diurnal  variations, 
irrespective  of  those  atmospheric  changes  which  affect  the 
weather,  it  is  desirable  in  making  comparative  observations 
to  do  so  at  fixed  hours  of  the  day.  Nine  or  ten  in  the 
morning  and  same  hour  in  the  evening  are  good  times  for 
observations  that  are  to  be  recorded.  These  are  about  the 
hours  of  daily  maxima  or  highest  readings  due  to  regular 
diurnal  variation. 

The  true  reading  of  the  barometer  is  the  height  at  which 
it  would  stand  if  placed  at  the  level  of  the  sea  at  high  tide; 
but,  as  barometers  are  always  placed  more  or  less  above 
this  level,  a  correction  for  elevation  is  necessary.  When 
the  height  of  the  place  is  known  this  correction  may  be 
made  by  adding  one  tenth  of  an  inch  to  the  actual  reading 
for  every  85  feet  of  elevation  up  to  510  feet;  the  same  for 
every  90  feet  between  510  and  1.140  feet,  for  every  95  feet 
between  1140  and  1900  feet,  and  for  every  100  feet  above 
this  and  within  our  mountain  limits.  This  simple  and 
easy  rule  is  sufficiently  accurate  for  practical  purposes. 
Thus,  a  Jbarometer  on  Bray  Head,  or  any  place  800  feet 
above  the  sea,  would  require  a  correction  of  six- tenths  for 
the  first  510  feet,  and  a  little  more  than  three-tenths  more 
for  the  remaining  290  feet.  Therefore,  if  such  a  barome- 
ter registered  the  pressure  at  29TV,  the  proper  sea-level 
reading  would  be  a  little  above  30  inches. 

The  most  important  prognostications  of  the  barometer 
are  those  afforded  by  what  is  called  the  "barometric  gra- 
dient or  incline,"  showing  the  up-hill  and  down-hill  direc- 
tion of  the  atmospheric  inequalities;  but  this  can  only  be 
ascertained  by  comparing  the  state  of  the  barometer  at  "dif- 
ferent stations  at  the  same  time.  Thus,  if  the  barometer  is 
one-fourth  of  an  inch  higher  at  Dublin  than  at  Galway, 
and  the  intermediate  stations  show  intermediate  heights, 
there  must  be  an  atmospheric  down-hill  gradient  from 
Dublin  to  Galway;  Dublin  must  be  under  the  upper  and 
Galway  under  the  lower  portion  of  a  great  atmospheric 
wave  or  current.  It  is  evident  that  when  there  is  thus 
more  air  over  Dublin  than  over  Galway,  there  must  follow 


THE  BAROMETER  AND   THE   WEATHER.        149 

(if  nothing  else  interferes)  a  flow  of  air  from  Dublin  to- 
wards Galway.  It  is  also  evident  that,  in  order  to  tell 
what  else  may  interfere,  we  must  know  the  atmospheric 
gradients  beyond  and  around  both  Dublin  and  Galway,  and 
for  considerable  distances. 

We  are  now  beginning  to  obtain  such  information  by 
organizing  meteorological  stations  and  observatories,  and 
transmitting  the  results  of  simultaneous  observations  by 
means  of  the  electric  telegraph  to  certain  head-quarters. 

The  subject  is  occupying  much  attention,  and  the  mana- 
gers of  those  splendid  monuments  of  British  energy — our 
daily  newspapers — are  publishing  daily  weather  charts,  and 
therefore  a  few  simple  explanations  of  the  origin,  nature, 
and  significance  of  such  charts  will  doubtless  be  appreciated 
by  our  readers. 

The  grand  modern  improvement  of  the  barometer,  the 
thermometer,  the  anemometer,  the  pluviometer,  etc.,  is 
that  of  making  them  "self-  registering."  We  are  told  that 
Cadmus  invented  the  art  of  writing,  and  we  honor  his 
memory  accordingly.  But  he  ventured  no  further  than 
teaching  human  beings  to  write.  Modern  meteorologists 
have  gone  much  further;  they  have  taught  the  winds  and 
the  rains  and  the  subtle  heavings  of  the  invisible  air  to 
keep  their  own  diaries,  to  write  their  own  histories  on 
paper  that  is  laid  before  them,  with  pencils  that  are  placed 
in  their  fleshless,  boneless,  and  shapeless  fingers.  This 
achievement  is  wrought  by  comparatively  simple  means. 
The  paper  is  wound  upon  an  upright  drum  or  cylinder, 
and  this  cylinder  is  made  to  revolve  by  clock-work,  in  such 
a  manner  that  a  certain  breadth  travels  on  during  the 
twenty-four  hours.  This  breadth  of  paper  is  divided  by 
vertical  lines  into  twenty-four  parts,  each  of  which  passes 
onward  in  one  hour.  Connected  with  the  barometer  is  a 
pencil  which,  by  means  of  a  spring,  presses  lightly  upon 
the  revolving  sheet,  and  this  pencil,  while  thus  pressing, 
rises  and  falls  with  the  mercury.  It  is  obvious  that,  in 
this  manner,  a  line  will  be  drawn  as  the  paper  moves.  If 
the  mercury  is  stationary,  the  line  will  be  horizontal — only 
indicating  the  movement  of  the  drum  ;  if  the  mercury  falls, 
the  line  will  slope  downwards ;  if  it  rises,  it  will  incline 


150 


SCIENCE  IN  SHORT  CHAPTERS. 


upwards.  By  ruling  horizontal  lines  upon  the  paper,  rep- 
resenting inches,  tenths,  and  smaller  fractions,  if  desired, 
the  whole  history  of  the  barometrical  movements  will  be 
graphically  recorded  by  the  waving  or  zigzag  lines  thus 
drawn  by  the  atmosphere  itself. 

The  subjoined  copy  of  the  Daily  Telegraph  Barometer 
Chart  represents,  on  a  small  scale,  a  four  days'  history  of 
barometrical  movements: 

The  large  figures  at  the  side  (29  and  30)  represent 
inches;  the  smaller  figures  tenths  of  inches. 

The  pressure  of  the  wind  is  similarly  pictured  by  means 
of  a  large  vane  which  turns  with  the  wind,  and  to  the  wind- 
ward face  of  which  a  flat  board  or  plate  of  metal,  one  foot 


5 

4 
3 

2 
I 

30 

5 

" 

FRI.   8 

SAT.    9 

SUN.  10 

MOM.  II 

^ 

^^ 

A 

\ 

\ 

^^\ 

r    ^x 

\ 

'f 

\    J^~ 

\ 

V 

V 

\ 

Vi.    ,  ,,  . 

- 

9,9 

square,  is  attached  perpendicularly.  As  the  wind  strikes 
this  it  presses  against  it  with  a  force  corresponding  to  a 
certain  number  of  pounds,  ounces,  and  fractions  of  an 
ounce.  A  spring  like  that  of  an  ordinary  spring  letter- 
balance  is  compressed  in  proportion  to  this  pressure.  This 
movement  of  the  spring  is  transmitted  mechanically  to  an- 
other pencil  like  the  above  described,  working  against  the 
same  drum  ;  thus  another  history  is  written  on  the  same 
paper — the  horizontal  lines  now  representing  fractions  of 
pounds  of  pressure,  instead  of  fractions  of  inches  of  mer- 
cury. 

It  has  been  found  that  if  a  semi -globular  cup  of  thin 
metal  is  exposed  to  the  wind,  the  pressure  upon  the  round 


THE  BAROMETER  AXD  THE   WEATHER.        151 

or  convex  side  of  the  hemisphere  is  equal  to  two  thirds  of 
that  upon  the  hollow  or  concave  side.  By  placing  four 
such  cups  upon  cross-arms,  and  the  arms  on  a  pivot,  the 
wind,  from  whatever  quarter  it  may  come,  will  always  blow 
them  round  with  their  convex  faces  foremost;  and  they 
will  move  with  one  third  of  the  actual  velocity  of  the  wind". 
By  a  simple  clock-work  arrangement,  these  arms  move  an- 
other pencil,  in  such  a  manner  that  it  strikes  the  paper 
hammer-fashion  every  time  the  wind  has  completed  a  jour- 
ney of  one  mile,  or  other  given  distance;  and  thus  a  series 
of  dots  upon  the  revolving  paper  records  the  velocity  of  the 
wind  according  to  their  distances  apart.  As  the  pressure 
of  the  wind  is  governed  by  two  factors,  viz.,  the  density 
and  velocity  of  the  moving  air,  the  relations  between  the 
barometer  curve,  the  pressure  curve,  and  the  velocity  dots, 
are  very  interesting. 

The  direction  of  the  wind  is  written  by  a  pencil  fixed  to 
a  quick  worm — a  screw-thread  upon  the  axis  of  the  vane. 
As  the  vane  turns  round — N.,  E.,  S.,  or  W. — it  screws 
the  pencil  up  or  down,  and  thus  the  horizontal  lines  first 
described  as  registering  tenths  of  inches  of  barometric  pres- 
sure do  duty  as  showing  the  points  of  the  compass  from 
which  the  wind  is  blowing  ;  and,  by  reference  to  the  zigzag 
line  drawn  by  this  pencil  of  the  wind,  its  direction  at  any 
particular  time  of  day  may  be  ascertained  as  certified  by  its 
own  sign-manual. 

The  wind-gauge  is  called  an  anemometer.  Connected 
with  this  is  the  pluviometer,  or  rain-gauge — an  upright 
vessel  with  an  open  mouth  of  measured  area — say  100  square 
inches.  This  receives  the  rain  that  falls.  By  means  of  a 
pipe  the  water  is  conveyed  to  a  vessel  having  a  surface  of — 
say  one  square  inch.  By  this  arrangement,  when  sufficient 
rain  has  fallen  to  cover  the  surface  of  the  earth  to  the  depth 
of  one  hundredth  of  an  inch,  the  little  vessel  below  will 
contain  water  one  inch  in  depth.  By  balancing  this  vessel 
at  the  end  of  a  long  arm,  it  is  made  to  preponderate  grad- 
ually as  the  weight  of  water  it  receives  increases,  and  finally, 
when  filled,  it  tips  over  altogether,  empties  itself,  and  then 
rises  to  its  starting  place  in  equilibrium.  To  the  other  end 
of  this  arm  a  pencil  is  attached,  which  inscribes  all  these 


152  SC1ESCE   IX  HHORT  CHAPTEl^. 

movements  on  the  revolving  paper,  and  thus  tells  the  his- 
tory of  the  rainfall.  The  line  is  zigzag  while  the  rain  is 
falling,  and  horizontal  while  the  weather  is  fair.  The 
amount  of  inclination  of  the  zigzag  line  measures  the  depth 
of  rain  by  means  of  the  same  ruled  lines  on  the  paper  as 
measure  the  height  of  the  barometer,  ete.  Every  time  the 
measuring  vessel  tips  over  a  perpendicular  line  is  drawn, 
and  the  pencil  resumes  its  starting  level.  The  papers  con- 
taining these  autographs  of  the  elements  may,  of  course, 
be  kept  as  permanent  records  for  reference  whenever  needed, 
or  the  results  may  be  tabitlated  in  other  forms. 

There  are  many  modifications  in  the  details  of  these  self- 
registering  instruments.  In  some  of  them  photography  is 
made  to  do  a  part  of  the  work.  The  above  description  in- 
dicates the  main  principles  of  their  construction,  without 
attempting  to  enter  upon  minute  details. 

Meteorological  observatories  are  provided  with  these  in- 
struments, and  all  nations  worthy  of  the  name  of  civilized 
co-operate  with  more  or  less  efficiency  in  providing  and  en- 
dowing such  establishments.  They  are  placed  in  suitable 
localities,  and  communicate. with  each  other,  and  with  cer- 
tain head-quarters,  by  means  of  the  electric  telegraph.  One 
of  these  head-quarters  is  the  Meteorological  Office,  at  Xo. 
116  Victoria  Street,  Westminster,  S.W.,  which  daily  re- 
ceives the  results  of  the  observations  taken  at  about  fifty 
stations  on  the  British  Islands  and  the  Continent.  The 
chief  observations  are  made  simultaneously — at  8  A.M. — 
and  telegraphed  in  cypher  to  London,  where  they  usually 
arrive  before  10  A.M.  As  they  come  in  they  are  marked 
down  in  their  proper  places  upon  a  large  chart,  and  when 
this  chart  is  sufficiently  completed,  a  condensed  or  abstract 
copy  is  made  containing  as  much  information  as  may  be 
included  in  the  small  newspaper  charts.  This  is  copied 
mechanically  on  a  reduced  scale  on  a  slab  on  which  t he- 
outline  chart  has  been  already  engraved.  This  engraving- 
completed,  casts  are  made  in  fusible  metal  with  the  black 
lines  in  relief,  for  printing  with  ordinary  type,  and  the 
casts  are  set  up  with  the  ordinary  newspaper  types,  and 
printed  with  the  letterpress  matter. 

The  engravings  overleaf  are  taken  from  two  of  the  news- 


THE  BAROMETER  AND    THE    WEATHER.        153 

paper  weather  charts  for  the  dates  of  October  5th  and  6th. 
They  are  enlarged  and  printed  more  clearly  than  the  ori- 
ginals, with  an  explanation  of  signs  at  foot  of  the  charts. 

It  will  be  observed  that,  in  the  chart  for  October  5th,  an 
isobar  of  29.2  runs  up  in  a  N.E.  direction  from  between  the 
Orkney  and  Shetland  islands,  crosses  the  North  Sea,  strikes 
the  coast  of  Norway  near  Bergen,  and  then  proceeds  on- 
wards towards  Throndhjem.  An  isobar  of  29.5  crosses 
Scotland,  following  very  nearly  the  line  of  the  Grampians, 
enters  the  North  Sea  about  Aberdeen,  and  crosses  to  Chris- 
tiansnnd;  then  runs  up  the  Skager  Rack  and  Christiania 
Fjord  towards  Christiania.  Another  isobar  of  29.8  crosses 
Ireland  through  Connaught  to  Dublin,  onward  across  Eng- 
land by  Liverpool  and  the  Humber,  over  the  North  Sea, 
and  through  Sleswig  to  the  Baltic.  These  three  are  nearly 
parallel;  but  now  we  find  another  isobar — that  of  30.2— 
taking  quite  a  different  course,  by  starting  from  the  Bay 
of  Biscay  about  Nantes ;  running  on  towards  Paris  and 
Strasbourg,  and  then  bending  sharp  round,  as  though 
frightened  by  the  Germans,  and  retreating  to  the  Gulf  of 
Lyons  by  an  opposite  course  to  that  on  which  it  started. 
On  the  following  day  all  has  changed;  the  northern  isobars 
are  running  down  south-eastwards  instead  of  north-east, 
and  are  remarkably  parallel.  In  the  left-hand  upper  corner 
of  this  chart  is  a  note  that  "our  west,  north,  and  eastern 
coasts  were  warned  yesterday"  Why  was  this?  It  was 
mainly  because  the  barometric  gradient  or  incline  was  so 
steep.  On  the  5th  there  was  one  inch  of  difference  between 
the  Orkneys  and  the  Bay  of  Biscay,  or  between  Bergen  and 
Paris,  while  the  barometer  was  still  falling  in  Norway  and 
at  the  same  moment  rising  in  Ireland  and  France.  On  the 
following  day  these  movements  culminated  in  a  gradient  of 
1.4 — nearly  one  and  a  half  inches — between  Cornwall  and 
the  ancient  capital  of  Norway. 

What  must  follow  from  this  condition  of  the  atmosphere? 
Clearly  a  great  flow  or  rush  of  air  from  the  south  towards 
the  comparatively  vacuous  regions  of  the  north.  The  gases 
of  our  atmosphere,  like  the  waters  of  the  ocean,  are  always 
struggling  to  find  their  level,  and  thereby  the  winds  are 
produced.  The  air  flows  from  all  sides  towards  the  lowest 


154  SCIENCE  Itf  SHORT  CHAPTERS. 

WEATHER-CHART,  OCTOBER  5,  1875. 


EXPLANATION  OP  WEATHER  CHART. 

In  these  charts  the  state  of  the  sea— whether  "rough,"  "smooth,"  "mode- 
rate," "slight,"  etc.,  is  marked  in  capital  letters;  and  the  state  of  the  weather 
—as  "clear."  "dull,"  "cloudy,"  "showery,"  etc..  in  small  letters.  The  direc- 
tion of  the  wind  is  indicated  by  the  arrows.  Unlike  the  arrows  of  a  vane,  these 
do  not  point  towards  the  direction  from  which  the  wind  is  coming,  but  are  fly- 


THE  BAROMETER  AND  THE  WEATHER.    155 

WEATHER  CHART,  OCTOBER  6,  1875. 


Our\N,N.ar\dEaslttn  Coasts 
vtre  natntlyesleria), 

Q 
0 


breeze,  by  an  arrow  with  two  barbs  and  no  feathers >  ;  4th.  A  gale,  by 

an  arrow  with  two  feathers  >• >  ;  and  5th.  A  violent  gale,  by  an  arrow 

with  four  feathers  » >  .    The  temperature— in  the  shado — is  marked  in 

figures  with  a  small  circle  to  the  right,  indicating  degrees— as  60°.  These  figures 
stand  in  the  places  where  the  observations  are  made.  The  other  figures— 
usually  with  decimals,  and  placed  at  the  end  of  the  dotted  lines— give  the 
height  of  the  barometer — the  dotted  line  showing  where  this  particular  height 
remained  the  same  at  the  time  of  observation.  These  dotted  lines  are  called 


156  SCIENCE  IN  SHORT  CHAPTERS. 

isobar.  But  what,  then,  must  be  the  course  of  the  wind? 
Will  it  be  in  straight  lines  towards  this  point?  If  so,  a 
strange  conflict  must  result  when  all  these  currents  meet 
from  opposite  directions.  What  will  follow  from  this 
conflict?  A  skillful  physicist  can  work  out  this  problem 
mathematically,  but  we  are  not  all  mathematicians,  some 
of  us  are  not  able  to  follow  his  formulas,  and,  therefore, 
will  do  better  by  resorting  to  simple  observation  of  other 
analogous  and  familiar  phenomena.  A  funnel  or  any  vessel 
with  a  hole  in  the  bottom  will  answer  our  purpose.  Let  us 
fill  such  a  vessel  with  water,  then  open  the  hole,  and  see 
what  will  be  the  course  of  the  water  when  it  is  struggling 
to  flow  from  all  sides  to  the  one  point  of  vacuity.  It  will 
very  soon  establish  a  vortex  or  whirlpool,  i.e.,  the  water 
instead  of  flowing  directly  by  straight  lines  from  the  sides 
to  the  centre  of  the  funnel,  will  take  a  roundabout,  spiral 
course,  and  thus  screw  its  way  down  the  outlet  of  the 
funnel. 

Tiiis  is  just  what  occurs  when  the  air  is  rushing  to  fill  a 
comparatively  vacuous  atmospheric  space.  It  moves  in  a 
spiral;  and  in  the  Northern  Hemisphere  this  spiral  always 
turns  in  the  same  way,  viz.,  in  the  opposite  direction  to  the 
hands  of  a  clock  when  flowing  inwards,  and  vice  versa,  or 
with  the  clock  hands,  when  the  air  is  overflowing. from  a 
centre  of  high  pressure. 

In  the  chart  for  October  5th  both  these  cases  are  illus- 
trated. North  of  Dublin  there  is  a  curvature  of  isobars 
and  an  inrush  of  winds  towards  a  northward  low  pressure, 
or  vacuous  region;  while  south  of  Dublin  the  isobar  tends 
sharply  round  a  high-pressure  focus,  and  the  overflowing 
wind  is  correspondingly  reversed  in  direction,  as  shown  by 
the  arrows. 

The  next  chart,  for  October  6th,  shows  that  the  overflow 
has  spread  northwards  as  far  as  Dublin,  and  the  high- 
pressure  focus  has  also  moved  northwards.  It  follows 
from  this  that  if  you  know  the  barometric  gradient,  and 
stand  with  your  left  hand  to  the  region  of  low  barometer 
and  your  right  hand  to  that  of  the  high  barometer,  the 
wind  will  blow  against  your  back,  i.e.,  you  will  face  the 
direction  of  the  wind,  or  of  those  flying  arrows  ou  the 


THE  BAROMETER  AND  THE  WEATHER.    157 

chart.  This  interesting  and  important  generalization  is 
called  "Buys  Ballot's  Law."  In  spite  of  the  proverbial 
fickleness  of  the  winds  this  simple  law  is -rarely  infringed, 
though  it  may  require  a  slight  modification  of  statement — 
inasmuch  as  the  wind  does  not  move  in  circles  round  the 
vacuous  space,  but  in  spirals,  and  thus  it  blows  not  quite 
square  to  the  back,  but  rather  obliquely,  or  a  little  on  the 
right  side.  This  is  shown  by  the  arrows  in  the  charts,  and 
is  most  strikingly  displayed  in  the  chart  for  October  6th, 
between  the  isobars  of  30.3  and  30.5.  To  take,  in  Ireland, 
the  position  required  by  Buys  Ballot's  Law,  one  must  have 
stood  facing  the  east,  and  accordingly,  the  westerly  wind 
would  then  blow  upon  one's  back.  In  Paris,  at  the  same 
moment,  the  position  would  be  facing  south-east,  and  the 
w.ind  was  curving  round  accordingly.  Further  south— at 
Bordeaux  or  the  Pyrenees — the  position  becomes  almost 
reversed,  i.e.,  facing  south-west,  and  the  wind  is  reversed 
in  equal  degree. 

Here,  then,  on  these  days  we  had  the  chief  conditions  of 
wind  and  rain,  a  steep  and  increasing  barometric  gradient, 
and  a  flow  over  our  islands  of  humid  air  from  the  south 
and  west  regions  of  the  great  Atlantic.  Strong  winds  and 
heavy  rains  did  follow  accordingly;  and  the  prophetic 
warnings  of  the  Meteorological  Office,  which  are  conveyed 
by  means  of  signals  displayed  on  prominent  parts  of  the 
coast,  were  fulfilled. 

Mr.  Scott,  the  Director  of  the  Meteorological  Office, 
tells  us  that  "The  degree  of  success  that  has  attended  our 
warnings  in  these  islands,  on  the  average  of  the  last  two 
years,  has  been  that  over  45  per  cent  have  been  followed  by 
severe  gales;  and  over  33  per  cent  in  addition  have  been 
followed  by  wind  too  strong  for  fishing-boats  and  yachts, 
though  in  themselves  not  severe  gales;  this  gives  a  total 
percentage  of  success  of  nearly  80." 

In  winter  the  movements  of  the  air  are  more  decided, 
and  the  changes  are  often  so  rapid  that  the  warning  some- 
times comes  too  late.  With  increased  means — i.e.,  more 
money  to  cover  additional  work,  and  more  stations — better 
results  might  be  obtained.  The  United  States  expend 
50,000?.  a  year  in  weather  telegraphy,  exclusive  of  salaries, 


158  SCIENCE  IN  SHORT  CHAPTERS. 

while  the  United  Kingdom  only  devotes  3,OOOZ.  a  year  to 
the  same  purpose.  The  difficulties  on  our  side  of  the 
Atlantic  are  greater  than  on  the  American  coasts,  on  ac- 
count of  the  greater  changeableness  of  our  weather — mainly 
due  to  the  more  irregular  distribution  of  land  and  water  on 
this  side.  This,  however,  instead  of  discouraging  national 
effort,  should  be  regarded  as  a  reason  for  increasing  it. 
The  greater  the  changes,  the  greater  is  the  need  for  warn- 
ings, and  the  greater  the  difficulty  the  greater  should  be 
the  effort.  With  our  multitude  of  coastguard  stations  and 
naval  men  without  employment,  we  ought  to  surpass  all 
the  world  in  such  a  work  as  this. 

Those  among  our  readers  who  are  sufficiently  interested 
in  this  subject  to  devote  a  little  time  to  it,  may  make  a 
very  interesting  weather  scrap-book  by  cutting  out  the 
newspaper  chart  for  each  day,  pasting  it  in  a  suitable 
album,  and  appending  their  own  remarks  on  the  weather 
at  the  date  of  publication,  i.e.  the  day  after  the  chart  ob- 
servations are  made.  Such  an  album  would  be  far  more 
interesting  than  the  postage  stamp  and  monogram  albums 
that  are  so  abundant. 

Parents  who  desire  their  children  to  acquire  habits  of 
systematic  observation,  and  to  cultivate  an  intelligent  in- 
terest in  natural  phenomena,  will  do  well  to  supply  such 
albums  to  their  sons  or  daughters,  and  to  hand  over  to 
them  the  daily  paper  for  this  purpose. 

The  Meteorological  Office  supplies  by  post  copies  of 
"  Daily  Weather  Reports"  to  any  subscriber  who  pays  five 
shillings  per  quarter  in  advance;  such  subscriptions  payable 
to  Robt.  H.  Scott,  Esq.,  Director  Meteorological  Office, 
116  Victoria  Street,  Westminster,  S.W. 

These  daily  reports  are  printed  on  a  large  double  sheet, 
on  one  half  of  which  are  four  charts,  representing  sepa- 
rately the  four  records  which  are  included  in  the  one 
smaller  newspaper  chart — viz.,  those  of  the  barometer,  the 
thermometer,  the  rain-gauge,  and  the  anemometer.  On 
the  other  half  of  the  sheet  is  a  detailed  separate  tabular 
statement  of  the  results  of  observations  made  at  the  fol- 
lowing stations : 


THE  CHEMISTRY  OF  BOG  RECLAMATION.      159 


Haparanda                    Wick 

Liverpool 

The  Helder 

HernOsand 

Nairn 

Valencia 

Cape  Griznez 

Stockholm 

Aberdeen 

Roche's  Point'  Brest 

Wisby 

Leith 

Pembroke 

L'Orient 

Christiausund 

Shields 

Portishead 

Rochefort 

Skudesnaes 

York 

Scilly 

Biarritz 

Ox5(Christiansund) 
8kaa;en  (The  Skaw) 

Scarborough 
Nottingham 

Plymouth 
Hurst  Castle 

Corunna 
Brussels 

Fan5 

Ardrossan 

Dover 

Charleville 

Cuxhaven 

Greencastle 

London 

Paris 

Sumburgh  Head 
Stornoway 
Thurso 

Donaghadee 
Kingstown 
Holyhead 

Oxford 
Cambridge 
Yarmouth 

Lvons 
Toulon 

On  Winds  and  Currents,  from  the  Admiralty  Physical 
Atlas. 

In  the  Northern  Hemisphere  the  effect  of  the  veering  of 
the  wind  on  the  barometer  is  according  to  the  following 
law: 

With  East,  South-east,  and  South  winds,  the  barometer 
falls. 

With  South-west  winds,  the  barometer  ceases  to  fall  and 
begins  to  rise. 

With  West,  North-west,  and  North  winds,  the  barometer 
rises. 

With  North-east  winds,  the  barometer  ceases  to  rise  and 
begins  to  fall. 

In  the  Northern  Hemisphere  the  thermometer  rises  with 
East,  South-east,  and  South  winds;  with  a  Soiith-west  wind 
it  ceases  to  rise  and  begins  to  fall;  it  falls  with  West,  North- 
west, and  North  winds;  and  with  a  North-east  wind  it  ceases 
to  fall  and  begins  to  rise. 


THE  CHEMISTRY  OF  BOG  EECLAMATION. 

THE  mode  of  proceeding  for  the  reclamation  of  bog- 
land  at  Kylemore  is  first  to  remove  the  excess  of  water  by 
"the  big  drain  and  the  secondary  drains,"  which  must  be 


160  SCIENCE  IN  SHORT  CHAPTERS. 

cut  deep  enough  to  go  right  down  to  the  gravel  below. 
These  are  supplemented  by  the  "sheep  drains,"  or  surface- 
drains,  which  are  about  twenty  inches  wide  at  top,  and 
narrow  downwards  to  six  inches  at  bottom.  They  run 
parallel  to  each  other,  with  a  space  of  about  ten  yards  be- 
tween, and  cost  one  penny  per  six  yards. 

This  first  step  having  been  made,  the  bog  is  left  for  two 
years,  during  which  it  drains,  consolidates,  and  sinks  some- 
what. If  the  bog  is  deep,  the  turf,  which  has  now  become 
valuable  by  consolidation,  should  be  cut. 

After  this  it  is  left  about  two  years  longer,  with  the 
drains  still  open.  Then  the  drains  are  cleared  and  deep- 
ened, and  a  wedge-shaped  sod,  too  wide  to  reach  the  bot- 
tom, is  rammed  in  so  as  to  leave  below  it  a  permanent 
tubular  covered  drain,  which  is  thus  made  without  the  aid 
of  any  tiles  or  other  outside  material.  The  drainage  is 
now  completed,  and  the  surface  prepared  for  the  important 
operation  of  dressing  with  lime,  which,  as  the  people  ex- 
pressively say,  "  boils  the  bog,"  and  converts  it  into  a  soil 
suitable  for  direct  agricultural  operations. 

Potatoes  and  turnips  may  now  be  set  in  "lazy  bed" 
ridges.  Mr.  Mitchell  Henry  save,  "Good  herbage  will 
grow  on  the  bog  thus  treated;  but  as  much  as  possible 
should  at  once  be  put  into  root-crops,  with  farm-yard 
manure  for  potatoes  and  turnips.  The  more  lime  you  give 
the  better  will  be  your  crop;  and  treated  thus  there  is  no 
doubt  that  even  during  the  first  year  land  so  reclaimed  will 
yield  remunerative  crops."  And  further,  that  "after  be- 
ing broken  up  a  second  time  the  laud  materially  improves, 
and  becomes  doubly  valuable."  Also  that  he  has  no  doubt 
that  "  all  bog-lauds  may  be  thus  reclaimed,  but  it  is  up- 
hill work,  and  not  remunerative  to  attempt  the  reclama- 
tion of  bogs  that  are  more  than  four  feet  in  depth." 

There  is  another  and  a  simpler  method  of  dealing  with 
bogs — viz.,  setting  them  into  narrow  ridges;  cutting  broad 
trenches  between  the  ridges;  piling  the  turf  cut  out  from 
these  trenches  into  little  heaps  a  few  feet  apart,  burning 
them,  and  spreading  the  ashes  over  the  ridges.  This  is 
rather  largely  practiced  on  the  coast  of  Donegal,  in  con- 
junction with  sea-weed  manuring,  and  is  prohibited  in 


THE  CHEMISTRY  OF  BOG  RECLAMATION.      161 

other  parts  of  Ireland  as  prejudicial  to  the  interests  of 
the  landlord. 

We  shall  now  proceed  to  the  philosophy  of  these  pro- 
cesses. 

First,  the  drainage.  Everybody  in  Ireland  knows  that 
the  bog  holds  water  like  a  sponge,  and  in  such  quantities 
that  ordinary  vegetation  is  rotted  by  the  excess  of  moisture. 
There  is  good  reason  to  believe  that  the  ancient  forests, 
which  once  occupied  the  sites  of  most  of  the  Irish  bogs, 
were  in  some  cases  destroyed  by  the  rotting  of  their  stems 
and  roots  in  the  excess  of  vegetable  soil  formed  by  genera- 
tions upon  generations  of  fallen  leaves,  which,  in  a  humid 
climate  like  that  of  Ireland,  could  never  become  drained  or 
air-dried. 

But  this  is  not  all.  There  is  rotting  and  rotting.  When 
the  rotting  of  vegetable  matter  goes  on  under  certain  con- 
ditions it  is  highly  favorable  to  the  growth  of  other  vegeta- 
tion, even  of  the  vegetation  of  the  same  kind  of  plants  as 
those  supplying  the  rotting  material.  Thus,  rotten  and 
rotting  straw  is  a  good  manure  for  wheat;  and  the  modern 
scientific  vine-grower  carefully  places  the  dressing  of  his 
vines  about  their  roots,  in  order  that  they  may  rot,  and 
supply  the  necessary  salts  for  future  growth.  The  same 
applies  generally;  rotting  cabbage-leaves  supply  the  best 
of  manure  for  cabbages;  rotting  rhubarb-leaves  for  rhubarb; 
rose-leaves  for  rose-trees;  and  so  on  throughout  the  vegeta- 
ble kingdom. 

Why,  then,  should  the  bog-rotting  be  so  exceptionally 
malignant?  As  I  am  not  aware  that  any  answer  has  been 

fiven  to  this  question,  I  will  venture  upon  one  of  my  own. 
t  appears  to  be  mainly  due  to  the  excess  of  moisture  pre- 
venting that  slow  combustion  of  vegetable  carbon  which 
occurs  wherever  vegetable  matter  is  heaped  together  and 
slightly  moistened.  We  see  this  going  on  in  steaming  dung- 
hills; in  hayricks  that  have  been  stacked  when  imperfectly 
dried;  in  the  spontaneous  combustion  of  damp  cotton  in 
the  holds  of  ships,  and  in  factories  where  cotton-waste  has 
been  carelessly  heaped;  and  in  cucumber-frames  and  the 
other  "  hot-beds"  of  the  gardener. 

In  ordinary  soils  this  combustion  goes  on  more  slowly, 


162  SCIENCE  IN  SHORT  CHAPTERS. 

but  no  less  effectively,  than  in  these  cases.  In  doing  so  it 
maintains  a  certain  degree  of  warmth  about  the  roots  of 
the  plants  that  grow  there,  and  gradually  sets  free  the  solu- 
ble salts  which  the  rotting  vegetables  contain,  and  supplies 
them  to  the  growing  plants  as  manure,  at  the  same  time 
forming  the  humus  so  essential  to  vegetation. 

A  great  excess  of  water,  such  as  soddens  the  bog,  pre- 
vents this,  and  also  carries  away  any  small  quantity  of 
soluble  nutritious  salts  the  soil  may  contain.  Thus,  in- 
stead of  being  warmed  and  nourished  by  slight  humidity, 
and  consequent  oxidation,  the  bog  soil  is  chilled  and 
starved  by  excess  of  water. 

The  absolute  necessity  of  the  first  operation — that  of 
drainage — is  thus  rendered  obvious;  and  I  suspect  that  the 
need  of  four  years'  rest,  upon  which  Mr.  MacAlister  insists, 
is  somehow  connected  with  a  certain  degree  of  slow  com- 
bustion that  accompanies  and  partially  causes  the  consol- 
idation of  the  bog.  I  have  not  yet  had  an  opportunity  of 
testing  this  by  inserting  thermometers  in  bogs  under  differ- 
ent conditions,  but  hope  to  do  so. 

The  liming  next  demands  explanation.  Mr.  Henry  says 
that  "it  leaves  the  soil  sweetened  by  the  neutralization  of  its 
acids." 

In  order  to  test  this  theory  I  have  digested  (i.e.,  soaked) 
various  samples  of  turf  cut  from  Irish  bogs  in  distilled 
water,  filtered  off  the  water,  and  examined  it.  I  find  that 
when  this  soaking  has  gone  far  enough  to  give  the  water 
a  coloring  similar  to  that  which  stands  in  ordinary  bogs, 
the  acidity  is  very  decided — quite  sufficiently  so  to  justify 
this  neutralization  theory  as  a  partial  explanation.  There  is 
little  reason  to  doubt  that  the  lime  is  further  effective  in 
enriching  the  soil;  or,  in  the  case  of  pure  bogs,  that  it  forms 
the  soil  by  disintegrating  and  decomposing  the  fibrous 
vegetable  matter,  and  thus  rendering  it  capable  of  assimila- 
tion by  the  crops. 

Another  effect  which  the  lime  must  produce  is  the 
liberation  of  free  ammonia  from  any  fixed  salts  that  may 
exist  in  the  bog. 

The  bog-burning  method  of  reclamation  is  easily 
explained.  In  the  first  place,  the  excessive  vegetable 


THE  CHEMISTRY  OF  BOG  RECLAMATION.      163 

encumbrance  is  reduced  in  quantity,  and  the  remaining 
ashes  supply  the  surface  of  the  bog  on  which  they  rest  with 
the  non-volatile  salts  that  originally  existed  in  the  burnt 
portions  of  the  bog.  In  other  words,  they  concentrate  in 
a  small  space  the  salts  that  were  formerly  distributed  too 
sparsely  through  the  whole  of  the  turf  which  was  burnt. 

As  there  are  great  differences  in  the  composition  of 
different  bogs,  especially  in  this  matter  of  mineral  ash,  it  is 
evident  that  the  success  of  this  method  must  be  very 
variable,  according  to  the  locality. 

On  discussing  this  method  with  Mr.  MacAlister  (Mr. 
Henry's  steward,  under  whose  superintendence  these  re- 
clamation works  are  carried  out),  he  informed  me  that  the 
bogs  on  the  Kylemore  estate  yield  a  very  small  amount  of 
ash — a  mere  impalpable  powder  that  a  light  breath  might 
blow  away;  that  it  was  practically  valueless,  excepting  from 
the  turf  taken  at  nearly  the  base  of  the  bog.  The  ash  I 
examined  where  the  bog-burning  is  extensively  practiced  in 
Donegal,  was  quite  different  from  this.  The  quantity  was 
far  greater,  and  its  substance  more  granular  and  gritty.  It, 
in  fact,  formed  an  important  stratum,  when  spread  over  the 
surface  of  the  ridges.  These  differences  of  composition 
may  account  for  the  differences  of  opinion  and  practice 
which  prevail  in  different  districts.  It  affords  a  far  more 
rational  explanation  than  the  assumption  that  all  such  con- 
tradictions arise  from  local  stup/dities. 

There  is  one  evil,  however,  which  is  common  to  all 
bog-burning  as  compared  with  liming — it  must  waste  the 
ammoniacal  salts,  as  they  are  volatile,  and  are  driven  away 
into  the  air  by  the  heat  of  combustion.  Somebody  may 
get  them  when  the  rain  washes  them  down  to  the  earth's 
surface  again;  but  the  burner  himself  obtains  a  very  small 
share  in  this  way. 

We  may  therefore  conclude  that  where  lime  is  near  at 
hand,  bog-burning  is  a  rude  and  wasteful,  a  viciously  indo- 
lent mode  of  reclamation.  It  is  only  desirable  where 
limestone  is  so  distant  that  the  expense  of  carriage  renders 
lime  practically  unattainable,  and  where  the  bog  itself  is 
rich  in  mineral  matter,  and  so  deep  and  distant  from  a  fuel 
demand,  that  it  may  be  burned  to  waste  without  an}' 


164  SCIENCE  IN  SHORT  CHAPTERS. 

practical  sacrifice.  Under  such  conditions  it  may  be  better 
to  burn  the  bog  than  leave  it  in  hopeless  and  worthless 
desolation. 

I  cannot  conclude  without  again  adverting  to  the  impor- 
tance of  this  subject,  and  affirming  with  the  utmost  empha- 
sis, that  the  true  Irish  patriot  is  not  the  political  orator, 
but  he  who  by  practical  efforts,  either  as  capitalist,  laborer, 
or  teacher,  promotes  the  reclamation  of  the  soil  of  Ireland, 
or  otherwise  develops  the  sadly  neglected  natural  resources 
of  the  country. 

With  Mr.  Mitchell  Henry's  permission  I  append  to  the 
above  his  own  description  of  the  results  of  his  experiment, 
originally  communicated  in  a  letter  to  the  Times ;  at  the 
same  time  thanking  him  for  his  kind  reception  of  a  stranger 
at  Kylemore  Castle,  and  the  facilities  he  afforded  me  for 
studying  the  subject  on  the  spot. 

"  The  interesting  account  you  lately  published  of  the  ex- 
tensive reclamations  of  His  Grace  the  Duke  of  Sutherland, 
under  the  title  of  '  An  Agricultural  Experiment,'  has  been 
copied  into  very  many  newspapers,  and  must  have  afforded 
a  welcome  relief  to  thousands  of  readers  glad  to  turn  for  a 
time  from  the  terrible  narratives  that  come  to  us  from  the 
east.  If  you  will  allow  me,  I  should  like  to  supplement 
your  narrative  by  a  rapid  sketch  of  what  has  been  done  here 
during  the  last  few  years,  on  a  much  humbler  scale,  in  the 
case  of  land  similar,  and  some  of  it  almost  identical,  with 
that  in  Sutherlandshire. 

"The  twelve  corps  d'armee  under  the  Duke's  command, 
in  the  shape  of  the  twelve  steam-engines  and  their  ploughs, 
engaged  in  subduing  the  stubborn  resistance  of  the  unre- 
claimed wilds  of  Sutherlandshire,  suggest  to  the  mind  the 
triumphs  of  great  warriors,  and  fill  us  with  admiration — 
not  always  excited  by  the  details,  of  great  battle;  but,  as 
great  battles  can  be  fought  seldom,  and  only  by  gigantic 
armies  and  at  prodigious  expense,  so  reclamation  on  such  a 
scale  is  far  beyond  the  opportunities  or  the  means  of  most 
of  us;  while  many  may,  perhaps,  be  encouraged  to  attempt 
work  similar  to  that  which  has  been  successfully  carried 
out  here. 


THE  CHEMISTRY  OF  BOG  RECLAMATION.        165 

"  And,  first  of  all,  a  word  as  to  the  all -important  matter 
of  cost.  Does  it  pay? 

"  Including  farm-buildings  and  roads,  the  reclamations 
here  have  cost  on  an  average  13Z.  an  acre,  which,  at  5  per 
cent,  means  an  annual  rent-charge  of  13s.,  to  which  is  to  be 
added  a  sum  of  from  Is.  to  3s.,  the  full  annual  value  of  the 
unreclaimed  land.  It  is  obvious  that  if  we  start  with  an 
outlay  of  3QI.  phis  the  Is.  to  3s.  of  original  rent,  such  an 
amount  would  usually  be  found  prohibitory;  but,  on  the 
other  hand,  excellent  profits  may  be  made  if  the  expenditure 
is  so  kept  down  that  the  annual  rent  is  not  more  than  from 
15s.  to  18s.  per  acre.  Before  entering  into  further  details; 
let  me  say  that  I  claim  no  credit  for  originality  in  what  has 
been  done.  The  like  has  been  effected  on  numerous  prop- 
erties in  Ireland  in  bygone  days,  and  is  daily  being  carried 
out  by  the  patient  husbandman  who  year  by  year  with  his 
spade  reclaims  a  little  bit  from  the  mountain  side.  And  you 
must  allow  me  emphatically  to  say  that  what  has  been  done 
here  economically  and  well  would  not  have  been  done  ex- 
cept for  the  prudence,  patience,  and  thoughtful  mind  of 
my  steward,  Archibald  MacAlister,  a  County  Antrim  man, 
descended  from  one  of  the  race  of  Highland  Catholic  Scotch 
settlers,  who  have  peopled  the  north  of  Ireland  and  added 
so  much  to  its  prosperity. 

"  The  Pass  of  Kylemore,  in  which  I  live,  is  undoubtedly 
favorably  situated  for  reclamation,  for  there  is  but  little 
very  deep  bog,  and  there  is  abundance  of  limestone.  In 
former  ages  it  must  have  been  an  estuary  of  the  sea,  with  a 
river  flowing  through  it,  now  represented  by  a  chain  of  lakes 
and  the  small  rapid  river  Dowris.  The  subsoil  is  sand, 
gravel,  and  schist  rock,  with  peat  of  varkms  depths  grown 
upon  it.  As  by  the  elevation  of  the  land  the  sea  long  ages 
ago  was  driven  back,  the  mossy  growth  of  peat  commenced, 
followed  by  pine  and  yew  trees,  of  which  the  trunks  and 
roots  are  abundantly  found;  but,  except  over  a  space  of 
about  400  acres,  every  tree  that  formerly  clothed  the  hill- 
sides has  been  cut  down  or  has  totally  disappeared.  The 
general  result  is  that  we  have  a  pass  several  miles  long, 
bounded  on  the  north  and  south  by  a  chain  of  rugged  moun- 
tains of  some  1500  or  1800  feet  in  height,  while  the  east  is 


166  SCIENCE  IN  SHORT  CHAPTERS. 

blocked  up  by  a  picturesque  chain  running  north  and  south, 
and  separating  the  Joyce  country  from  Connemara  proper, 
the  west  being  open  to  the  Atlantic.  The  well-known  Kil- 
lery  Bay,  or  Fiord,  would,  I  doubt  not,  present  an  exact 
resemblance  to  Kylemore  if  the  sea,  which  now  flows  up  to 
its  head,  were  driven  out.  There  are  miles  of  similar  coun- 
try in  Ireland,  waiting  only  for  the  industry  of  man,  where, 
as  here,  there  exist  extensive  stretches  of  undulating  eskers, 
covered  with  heather  growing  on  the  light  clay,  with  a  basis 
of  gravel  or  sand. 

"A  considerable  difference  exists  between  the  reclamation 
of  the  flat  parts,  where  the  bog  is  pretty  deep,  and  the  hill- 
sides, where  there  is  little  or  no  bog.  Yet  it  is  to  be  remem- 
bered that  bog  is  nothing  more  than  vegetable  matter  in  a 
state  of  partial  decomposition,  and  holding  water  like  a 
sponge.  The  first  thing  is  to  remove  the  water  by  drains, 
some  of  which — that  is,  the  big  drain  and  the  secondary 
drains — must  go  right  down  to  the  gravel  below;  but  the 
other  drains — called  sheep-drains — need  not,  and,  indeed, 
must  not  be  cut  so  deep.  The  drains  are  cut  wedge-shape 
by  what  are  called  Scotch  tools,  which  employ  three  men — 
two  to  cut  and  one  to  hook  out  the  sods;  and  all  that  is 
requisite  to  form  a  permanent  drain  is  to  replace  the  wedge- 
shaped  sod,  and  ram  it  down  between  the  walls  of  the  drain, 
where  it  consolidates  and  forms  a  tube  which  will  remain 
open  for  an  indefinite  number  of  years.  We  haYe  them  here 
as  good  as  new,  made  twenty-five  years  ago;  and  at  Cbat 
Moss,  in  Lancashire,  they  are  much  older.  After  land  has 
been  thus  drained — but  not  too  much  drained,  or  it  will 
become  dry  turf — the  surface  begins  to  sink;  what  was  tumid 
settles  down,  an€  in  the  course  of  a  few  months  the  land 
itself  becomes  depressed  on  the  surface  and  much  consoli- 
dated. Next  it  is  to  be  dug  by  spade-labor  or  ploughed. 
We  use  oxen  largely  for  this  purpose,  and,  strange  to  say, 
the  best  workers  we  find  to  be  a  cross  with  the  Alderney,  the 
result  being  a  light,  wiry  little  animal,  which  goes  gayly  over 
the  ground,  is  easy  to  feed,  and  is  very  tractable.  The  oxen 
are  trained  by  the  old  wooden  neck-yoke;  but,  when  well 
broken,  work  in  collars,  which  seem  more  easy  to  them. 
Horses  on  very  soft  land  work  well  in  wooden  pattens. 


THE  CHEMISTRY  OF  BOG   RECLAMATION.      167 

After  the  land  has  been  broken  up,  a  good  dressing  of  lime 
is  to  be  applied  to  it,  and  this,  in  the  expressive  language  of 
the  people  here,  'boils  the  bog  ' — that  is,  the  lime  causes  the 
vegetable  matter,  formerly  half  decomposed,  to  become  con- 
verted into  excellent  manure.  This  leaves  the  soil  sweetened 
by  the  neutralization  of  its  acids,  and  in  a  condition  pretty 
easily  broken  up  by  the  chain-harrow;  or,  what  is  better 
still,  by  Randall's  American  revolving  harrow. 

"Good  herbage  will  grow  on  bog  thus  treated,  but  as 
much  as  possible  should  at  once  be  put  into  root-crops,  with 
farmyard  manure  for  potatoes  and  turnips.  The  more  lime 
you  give  the  better  will  be  your  crop,  and,  treated  thus, 
there  is  no  doubt  that  even  during  the  first  year,  land  so  re- 
claimed will  yield  remunerative  crops.  People  ask,  '  But 
will  not  the  whole  thing  go  back  to  bog  ?'  Of  course  it  will 
if  not  kept  under  proper  rotation,  which  we  find  to  be  one 
of  five  years — namely,  roots  followed  by  oats,  laid  down  with 
clover  and  grass  seed,  which  remains  for  two  years.  After 
being  broken  up  a  second  time,  the  land  materially  im- 
proves and  becomes  doubly  valuable.  I  have  no  doubt  that 
all  bog-lands  may  be  thus  reclaimed,  but  it  is  up-hill  work 
and  not  remunerative  to  attempt  the  reclamation  of  bogs 
that  are  more  than  four  feet  in  depth. 

"  And  here  I  will  make  a  remark  as  to  the  effects  of 
drainage  in  a  wet  country.  By  no  means  does  the  whole 
effect  result  from  raising  the  temperature  of  the  soil;  there 
is  something  else  as  important,  and  that  is  the  supply  of 
ammonia,  brought  down  from  the  skies  in  the  rain,  which, 
with  other  fertilizing  matter,  is  caught,  detained,  and  ab- 
sorbed in  the  soil.  A  well-drained  field  becomes,  in  fact, 
just  like  a  water-meadow  over  which  a  river  flows  for  a  part 
of  a  year;  and  thus  the  very  wetness  of  the  climate  may  be 
made  to  reduce  the  supply  of  ammoniacal  manures,  so  ex- 
pensive to  buy. 

"The  porous,  well-drained  soil  carries  quickly  off  the 
superfluous  moisture,  while  the  ammonia  is  absorbed  by  the 
roots  and  leaves  of  the  plants.  An  excessive  bill  for  am- 
moniacal manures  has  been  the  ruin  of  many  a  farmer;  and 
our  aim  in  Ireland  should  be  to  secure  good  crops  by 
thorough  drainage  and  constant  stirring  of  the  soil,  without 


168  SCIENCE  IN  SHORT  CHAPTERS. 

much  outlay  for  concetrated  manures.  At  the  same  time 
I  ought  to  remark  that  we  have  grown  excellent  potatoes  by 
using  57.  worth  per  acre  of  superphosphate  and  nitrate  of 
soda  in  cases  in  which  our  farmyard  manure  has  fallen  short. 

"  The  reclamation  of  mountain-laud  as  distinguished 
from  hog-land  can  hest  be  illustrated  by  a  record  of  what 
has  been  accomplished  on  two  farms  here.  Three  years 
ago  the  leases  of  two  upland  farms  fell  in,  and  I  took  them 
into  my  own  hands.  The  first  consists  of  600  acres,  one- 
half  a  nearly  level  flat  of  deepish  bog  running  alongside 
the  river,  the  other  half  moor  heath,  which  with  difficulty 
supported  a  few  sheep  and  cattle. 

."  There  had  never  been  any  buildings  on  this  land,  nor 
had  a  spade  ever  been  put  into  it;  and  the  tenant,  being 
unable  to  pay  his  rent  of  151.  a  year  for  the  600  acres,  was 
glad  to  give  it  up  for  a  moderate  consideration.  The  first 
thing  accomplished  was  to  fence  and  drain  thoroughly  as 
before  described,  and  the  best  half  of  the  land  was  then 
divided  into  forty-acre  fields.  Exactly  now  two  years  ago — 
on  September  15th — a  little  cottage  and  a  stable  for  a  pair 
of  horses  and  a  pair  of  bullocks  was  completed  and  tenanted 
by  two  men  and  a  boy.  They  ploughed  all  the  week  and 
came  home  on  Saturdays  to  draw  their  supply  of  food  and 
fodder  for  the  ensuing  seven  days,  thus  approximating  very 
nearly  to  the  position  of  settlers  in  a  new  country.  We 
limed  all  the  land  we  could,  manured  part  of  it  with  sea- 
weed and  part  with  the  farm  manure  made  by  the  horses 
and  oxen  which  were  at  work,  and  cropped  with  roots  such 
as  turnips  and  potatoes.  A  good  portion  we  sowed  with 
oats  out  of  the  lea,  but  the  most  satisfactory  crop  we  found 
to  be  rape  and  grasses  mixed,  for  on  the  best  of  the  land 
they  form  at  once  an  excellent  permanent  pasture.  We 
have  now  had  two  crops  from  this  land;  and  I  venture  to 
say  that  the  thirteen  stacks  of  oats  and  hay  gathered  in  in 
good  condition,  and  the  turnips  and  roots  now  growing, 
which  are  not  excelled  in  the  county  Gal  way — except  those 
of  Lord  Clancarty  at  Ballinasloe,  who  has  grown  110  tons 
of  turnips  to  the  Irish  acre,  equal  to  upwards  of  68  tons  to 
the  acre  here— present  a  picture  most  gratifying  and  cheer- 
ing in  every  way. 


THE  CHEMISTRY  OF  BOG  RECLAMATION.      169 

"  The  second  farm,  of  240  acres,  which  adjoins  this,  had 
a  good  building  on  it;  but,  having  been  let  on  lease  at 
about  10s.  an  acre  to  a  large  grazier  whose  stock-in-trade 
was  a  horse,  a  saddle,  and  a  pair  of  shears,  had  not  been 
cultivated  or  improved. 

"  Similar  proceedings  on  this  farm  have  produced  simi- 
lar results;  and,  if  now  let  in  the  market,  I  have  no  doubt 
that  after  two  years  of  good  treatment  these  farms  would 
be  let  at  20s.  an  acre,  and  I  do  not  despair  of  doubling  this 
figure  in  the  course  of  time. 

"  The  exact  weight  of  the  turnip  crop  this  season  is,  on 
raw  bog,  drained,  limed,  and  cropped  this  year  for  the  first 
time,  24  tons  per  acre;  manure,  seaweed.  On  land 
ploughed  but  not  cropped,  last  year  23£  tons;  mixed 
mineral  manure.  On  land  from  which  a  crop  of  oats  had 
previously  been  taken,  29  tons;  manure>  farmyard,  with  3 
cwt.  per  acre  mineral  manure. 

"  Last  year  my  excellent  steward,  Mr.  MacAlister,  visited 
the  Duke  of  Sutherland's  reclamations  in  Scotland,  and 
was  kindly  and  hospitably  received.  He  found  the  land 
and  the  procedure  adopted  almost  identical,  with  the  con- 
viction that  oxen  and  horses  will  suit  us  better  at  the 
present  time  than  steam  culture,  chiefly  on  the  score  of 
economy.  He  also  visited  the  Bridgewater  Estate  at  Chat 
Moss,  near  Manchester,  where  so  much  has  been  done  to 
bring  the  deep  peat  into  cultivation,  and  he  found  the  sys- 
tem that  has  been  followed  there  for  so  many  years  to  be 
like  that  described  above,  marl,  however,  being  used  in  the 
place  of  lime." 

At  the  time  of  my  visit  to  Kylemore  the  hay  crops  were 
down  and  partly  carried  on  the  reclaimed  bog-land  above, 
described.  The  contrast  of  its  luxuriance  with  the  dark 
and  dreary  desolation  of  the  many  estates  I  had  seen  during 
three  summers'  wanderings  through  Ireland  added  further 
proof  of  the  infamy  of  the  majority  of  Irish  landlords,  by 
showing  what  Ireland  would  have  been  had  they  done  their 
duty. 


170  SCIENCE  IN  SHORT  CHAPTERS. 


AERIAL  EXPLORATION  OF  THE  ARCTIC 
REGIONS. 

ON  our  own  hemisphere,  and  separated  from  our  own 
coasts  by  only  a  few  days'  journey  on  our  own  element, 
there  remains  a  blank  circle  of  iinexplored  country  above 
800  miles  in  diameter.  We  have  tried  to  cross  it,  and 
have  not  succeeded.  Nothing  further  need  be  said  in  re- 
ply to  those  who  ask,  "  Why  should  we  start  another  Arctic 
Expedition?" 

The  records  of  previous  attempts  to  penetrate  this  area 
of  geographical  mystery  prove  the  existence  of  a  formidable 
barrier  of  mountainous  land,  fringed  by  fjords  or  inlets, 
like  those  of  Norway,  some  of  which  may  be  open,  though 
much  contracted  northward,  like  the  Yestfjord  that  lies 
between  the  Lofoden  Islands  and  the  mainland  of  Scandin- 
avia. The  majority  evidently  run  inland  like  the  ordinary 
Norwegian  fjords  or  the  Scotch  firths,  and  terminate  in 
land  valleys  that  continue  upwards  to  fjeld  regions,  or 
elevated  humpy  land  which  acts  as  a  condenser  to  the 
vapor-laden  air  continually  flowing  towards  the  Pole  from 
the  warmer  regions  of  the  earth,  and  returning  in  lower 
streams  when  cooled.  The  vast  quantities  of  water  thus 
condensed  fall  upon  these  hills  and  table  lauds  as  snow 
crystals.  What  becomes  of  this  everlasting  deposit? 

Unlike  the  water  that  rains  on  temperate  hill-sides,  it 
cannot  all  flow  down  to  the  sea  as  torrents  and  liquid  rivers, 
but  it  does  come  down  nevertheless,  or  long  ere  this  it 
would  have  reached  the  highest  clouds.  It  descends  mainly 
as  glaciers,  which  creep  down  slowly,  but  steadily  and  ir- 
resistibly, filling  up  the  valleys  on  their  way;  and  stretch- 
ing outwards  into  the  fjords  and  channels,  which  they 
block  up  with  their  cleft  and  chasmed  crystalline  angular 
masses  that  still  creep  outwaid  to  the  sea  until  they  float, 
and  break  off  or  "calve"  as  mountainous  icebergs  and 
smaller  masses  of  ice. 

These  accumulations  of  ice  thus  formed  on  land  consti- 


ARCTIC  REGIONS -AERIAL  EXPLORATIONS.      171 

tute  the  chief  obstructions  that  bar  the  channels  and  inlets 
fringing  the  unknown  Polar  area.  The  glacier  fragments 
above  described  are  cemented  together  in  the  winter  time 
by  the  freezing  of  the  water  between  them.  An  open 
frozen  sea,  pure  and  simple,  instead  of  forming  a  barrier 
to  arctic  exploration,  would  supply  a  most  desirable  high- 
way. It  must  not  be  supposed  that,  because  the  liquid 
ocean  is  ruffled  by  ripples,  waves,  and  billows,  a  frozen  gea 
would  have  a  similar  surface.  The  freezing  of  such  a  sur- 
face could  only  start  at  the  calmest  intervals,  and  the  ice 
would  shield  the  water  from  the  action  of  the  wave-making 
wind,  and  such  a  sea  would  become  a  charming  skating 
rink,  like  the  Gulf  of  Bothnia,  the  Swedish  and  Norwe- 
gian lakes,  and  certain  fjords,  which,  in  the  winter  time, 
become  natural  ice-paved  highways,  offering  incomparable 
facilities  for  rapid  locomotion.  In  spite  of  the  darkness 
and  the  cold,  winter  is  the  traveling  season  in  Sweden  and 
Lapland.  The  distance  that  can  be  made  in  a  given  time 
in  summer  with  a  wheeled  vehicle  on  well-made  post  roads 
can  be  covered  in  half  the  time  in  a>pulk  or  reindeer  sledge 
drawn  over  the  frozen  lakes.  From  Spitsbergen  to  the 
Pole  would  be  an  easy  run  of  five  or  six  days  if  nothing 
but  a  simply  frozen  sea  stood  between  ('hem. 

This  primary  physical  fact,  that  arctic  navigators  have 
not  been  stopped  by  a  merely  frozen  sea,  but  by  a  combina- 
tion of  glacier  fragments  with  the  frozen  water  of  bays, 
and  creeks,  and  fjords,  should  be  better  understood  than  it 
is  at  present;  for  when  it  is  understood,  the  popular  and 
fallacious  notion  that  the  difficulties  of  arctic  progress  are 
merely  dependent  on  latitude,  and  must  therefore  increase 
with  latitude,  explodes. 

It  is  the  physical  configuration  of  the  fringing  zone  of  the 
arctic  regions,  not  its  mere  latitude,  that  bars  the  way 
to  the  Pole. 

I  put  this  in  italics  because  so  much  depends  upon  it — 
I  may  say  that  all  depends  upon  it — for  if  this  barrier  can 
be  scaled  at  any  part  we  may  come  upon  a  region  as  easily 
traversed  as  that  part  of  the  Arctic  Ocean  lying  between 
the  North  Cape  and  Spitzbergen,  which  is  regularly  navi- 
gated every  summer  by  hardy  Norsemen  in  little  sailing 


172  SCIENCE  IN  SHORT  CHAPTERS. 

sloops  of  30  to  40  tons  burden,  and  only  six  or  eight  pair 
of  hands  on  board  ;  or  by  overland  traveling  as  easily  as  the 
Arctic  winter  journey  between  Tornea  and  Alten.  This 
trip  over  the  snow-covered  mountains  is  done  in  five  or  six 
days,  at  the  latter  end  of  every  November,  by  streams  of 
visitors  to  the  fair  at  Alten,  in  latitude  70°,  3^  degrees  N. 
of  the  Arctic  circle ;  its  distance,  430  miles,  is  just  about 
equal  to  that  which  stands  between  the  North  Pole  and 
the  northernmost  reach  of  our  previous  Arctic  expedi- 
tious. One  or  the  other  of  the  above-named  conditions, 
or  an  enclosed  frozen  Polar  ocean,  is  what  probably  exists 
beyond  the  broken  fjord  barrier  hitherto  explored  ;  a  con- 
tinuation of  such  a  barrier  is,  in  fact,  almost  a  physical 
impossibility;  and  therefore  the  Pole  will  be  ultimately 
reached,  not  by  a  repetition  of  such  weary  struggles  as 
those  which  ended  in  the  very  hasty  retreat  of  our  last 
expedition,  but  by  a  bound  across  about  400  miles  of  open 
or  frozen  Polar  ocean,  or  a  rapid  sledge-run  over  snow- 
paved  fields  like  those  so  merrily  traversed  in  Arctic  Nor- 
way by  festive  bonders  and  their  families  on  their  way  to 
Yule-time  dancing  parties. 

Reference  to  a  map  of  the  circumpolar  regions,  or,  better, 
to  a  globe,  will  show  that  the  continents  of  Europe,  Asia, 
and  America  surround  the  Pole,  and  hang,  as  it  were,  down- 
wards or  southwards  from  a  latitude  of  70°  and  upwards. 
There  is  but  one  wide  outlet  for  the  accumulations  of 
Polar  ice,  and  that  is  between  Norway  and  Greenland, 
with  Iceland  standing  nearly  midway.  Davis's  and  Beh- 
riug's  Straits  are  the  narrower  openings  :  the  first  may 
be  only  a  fjord,  rather  than  an  outlet.  The  ice-block, 
or  crowding  together  and  heaping  up  of  the  glacier  frag- 
ments and  bay  ice,  is  thus  explained. 

Attempts  of  two  kinds  have  been  made  to  scale  this  icy 
barrier.  Ships  have  sailed  northwards,  threading  a  dan- 
gerous course  between  the  floating  icebergs  in  the  sum- 
mer, and  becoming  fast  bound  in  winter,  when  the  nar- 
row spaces  of  brackish  water  lying  between  these  masses 
of  land  ice  become  frozen,  and  the  "  ice-foot"  clinging  to 
the  shore  stretches  out  seaward  to  meet  that  on  the  oppo- 
site side  of  the  fjbrd  or  channel.  The  second  method, 


ARCTIC  REGIONS— AERIAL  EXPLORATIONS.     1?'! 

usually  adopted  as  supplementary  to  the  first,  is  that  of 
dragging  sledges  over  these  glacial  accumulations.  The 
pitiful  rate  of  progress  thus  attainable  is  shown  by  the 
record  of  the  last  attempt,  when  Commander  Markham 
achieved  about  one  mile  per  day,  and  the  labor  of  doing 
this  was  nearly  fatal  to  his  men.  Any  tourist  who  has 
crossed  or  ascended  an  Alpine  glacier  with  only  a  knap- 
sack to-  carry,  can  understand  the  difficulty  of  dragging  a 
cartload  of  provisions,  etc.,  over  such  accumulations  of 
iceberg  fragments  and  of  sea-ice  squeezed  and  crumbled 
up  between  them.  It  is  evident  that  we  must  either  find 
a  natural  breach  in  this  Arctic  barrier  or  devise  some  other 
means  of  scaling  it. 

The  first  of  these  efforts  has  been  largely  discussed  by 
the  advocates  of  rival  routes.  I  will  not  go  into  this  ques- 
tion at  present,  but  only  consider  the  alternative  to  all  land 
routes  and  all  water  routes,  viz. :  that  by  the  other  available 
element — an  aerial  route — as  proposed  to  be  attempted  in 
the  new  Arctic  expedition  projected  by  Commander  Cheyne, 
and  which  he  is  determined  to  practically  carry  out,  pro- 
vided his  own  countrymen,  or,  failing  them,  others  more 
worthy,  will  assist  him  with  the  necessary  means  of  doing 
so. 

To  reach  the  Pole  from  the  northernmost  point  al- 
ready attained  by  our  ships  demands  a  journey  of  about 
400  miles,  the  distance  between  London  and  Edinburgh. 
With  a  favorable  wind,  a  balloon  will  do  this  in  a  few  hours, 
On  November  27,  1870,  Captain  Eoher  descended  near 
Lysthuus,  in  Hitterdal  (Norway),  in  the  balloon  "Yille 
d'Orlcans,"  having  made  the  journey  from  Paris  in  fif- 
teen hours.  The  distance  covered  was  about  900  miles, 
more  than  double  the  distance  between  the  Pole  and  the 
accessible  shores  of  Greenland. 

On  November  7,  1836,  Messrs.  Holland,  Mason,  and 
Green  ascended  from  Vauxhall  Gardens,  at  1.30  P.M., 
with  a  moderate  breeze,  and  descended  eighteen  hours 
afterwards  "  in  the  Duchy  of  Nassau,  about  two  leagues 
from  the  town  of  Weilburg,"  the  distance  in  a  direct  line 
being  about  500  miles.  A  similar  journey  to  this  would 
carry  Commander  Cheyne  from  his  ship  to  the  North  Pole, 


174  SCIENCE  IN  SHORT  CHAPTERS. 

or  thereabouts,  while  a  fresh  breeze  like  that  enjoyed  by 
Captain  Roher  would,  in  the  same  time,  carry  him  clear 
across  the  whole  of  the  circumpolar  area  to  the  neighbor- 
hood of  Spitzbergen,  and  two  or  three  hours  more  of  simi- 
lar proceeding  would  land  him  in  Siberia  or  Finland,  or 
even  on  the  shores  of  Arctic  Norway,  where  he  could  take 
the  Vadso  or  Hammerfest  packet  to  meet  one  of  Wilson's 
liners  at  Trondhjem  or  Bergen,  and  thus  get  from  the 
North  Pole  to  London  in  ten  days. 

Lest  any  of  my  readers  should  think  that  I  am  writing 
this  at  random,  I  will  supply  the  particulars.  I  have  be- 
fore me  the  "Norges  Communicationer"  for  the  present 
summer  season  of  1880.  Twice  every  week  a  passenger 
excursion  steam  packet  sails  round  the  North  Cape  each 
way,  calling  at  no  less  than  twenty  stations  on  this  Arctic 
face  of  Europe  to  land  and  embark  passengers  and  goods. 
By  taking  that  which  stops  at  Gjesvaer  (an  island  near  the 
foot  of  the  North  Cape)  on  Saturday,  or  that  which  starts 
from  Hammerfest  on  Sunday  morning,  Trondhjem  is 
reached  .on  Thursday,  and  Wilson's  liner,  the  "Tasso/' 
starts  on  the  same  day  for  Hull,  "average  passage  seventy 
hours."  Thus  Hammerfest,  the  northernmost  town  in 
the  world,  is  now  but  eight  days  from  London,  including 
a  day's  stop  at  Tromso,  the  capital  of  Lapland,  which  is 
about  3  degrees  N.  of  the  Arctic  circle,  and  within  a  week 
of  London.  At  Captain  Roher's  rate  of  traveling  Tromso 
would  be  but  twenty-three  hours  from  the  Pole. 

These  figures  are,  of  course,  only  stated  as  possibilities 
on  the  supposition  that  all  the  conditions  should  be  favor- 
able, but  by  no  means  as  probable. 

What,  then,  are  the  probabilities  and  the  amount  of  risk 
that  will  attend  an  attempt  to  reach  the  Pole  by  an  aerial 
route  ? 

I  have  considered  the  subject  carefully,  and  discussed 
it  with  many  people ;  the  result  of  such  reflection  and 
conversation  is  a  conviction  that  the  prevalent  popular 
estimate  of  the  dangers  of  Commander  Cheyne's  project 
extravagantly  exaggerates  them  on  almost  all  contingencies. 
I  do  not  affirm  that  there  is  no  risk,  or  that  the  attempt 
should  be  made  with  only  our  present  practical  knowledge 


ARCTIC  REGIONS— AERIAL    EXPLORATIONS.     175 

of  the  subject,  but  I  do  venture  to  maintain  that,  after 
making  proper  preliminary  practical  investigations  at  home, 
a  judiciously  conducted  aerostatic  dash  for  the  Pole  will  be 
far  less  dangerous  than  the  African  explorations  of  Living- 
stone, Stanley,  and  others  that  have  been  accomplished  and 
are  proposed.  And  further,  that  a  long  balloon  journey  start- 
ing in  summer-time  from  Smith's  Sound,  or  other  suit- 
able Arctic  station,  would  be  less  dangerous  than  a  corres- 
ponding one  started  from  London  ;  that  it  would  involve 
less  risk  than  was  incurred  by  Messrs.  Holland,  Mason, 
and  Green,  when  they  traveled  from  Yauxhall  Gardens 
to  Nassau. 

The  three  principal  dangers  attending  such  a  balloon 
journey  are :  1st.  The  variability  of  the  wind.  2d.  The 
risk  of  being  blown  out  about  the  open  ocean  beyond  the 
reach  of  land.  3d.  The  utter  helplessness  of  the  aeronau- 
during  all  the  hours  of  darkness.  I  will  consider  these  set 
riatim  in  reference  to  Arctic  ballooning  versus  Yauxhall 
or  Crystal  Palace  ballooning. 

As  regards  the  first  danger,  Vauxhall  and  Sydenham  are  in 
a  position  of  special  disadvantage,  and  all  the  ideas  we  Eng- 
lishmen may  derive  from  our  home  ballooning  experience 
must  tend  to  exaggerate  our  common  estimate  of  this  danger, 
inasmuch  as  we  are  in  the  midst  of  the  region  of  variable 
winds,  and  have  a  notoriously  uncertain  climate,  due  to  this 
local  exaggeration  of  the  variability  of  atmospheric  move- 
ments. If  instead  of  lying  between  the  latitudes  of  50°  and 
60°,  where  theN.E.  Polar  winds  just  come  in  collision  with 
the  S.W.  tropical  currents,  and  thereby  effect  our  national 
atmospheric  stir-about,  we  were  located  between  10°  and  30° 
(where  the  Canary  Islands  are,  for  example),  our  notions  on 
the  subject  of  balloon  traveling  would  be  curiously  dif- 
ferent. The  steadily  blowing  trade-wind  would  long  ere 
this  have  led  us  to  establish  balloon  mails  to  Central  and 
South  America,  and  balloon  passenger  expresses  for  the 
benefit  of  fast-going  people  or  luxurious  victims  of  sea-sick- 
ness. To  cross  the  Atlantic — three. thousand  miles — in 
forty-eight  hours,  would  be  attended  with  no  other  diffi- 
culty than  the  cost  of  the  gas,  and  that  of  the  return  car- 
riage of  the  empty  balloon. 


176  SCIENCE  IN  SHORT  CHAPTERS. 

It  is  our  exceptional  meteorological  position  that  has 
generated  the  popular  expression  "  as  uncertain  as  the  wind." 
We  are  in  the  very  centre  of  the  region  of  meteorological 
uncertainties,  and  cannot  go  far,  either  northward  or 
southward,  without  entering  a  zone  of  greater  atmospheric 
regularity,  where  the  direction  of  the  wind  at  a  given  season 
may  be  predicted  with  more  reliability  than  at  home.  The 
atmospheric  movements  in  the  Arctic  regions  appear  to  be 
remarkably  regular  and  gen  tie  during  the  summer  and  winter 
months,  and  irregular  and  boisterous  in  spring  and  autumn. 
A  warm  upper  current  flows  from  the  tropics  towards  the 
Pole,  and  a  cold  lower  one  from  the  Arctic  circle  towards 
the  equator.  Commander  Cheyne,  who  has  practical 
experience  of  these  Arctic  expeditions,  and  has  kept  an 
elaborate  log  of  the  wind,  etc.,  which  he  has  shown  me, 
believes  that,  by  the  aid  of  pilot  balloons  to  indicate  the 
currents  at  various  heights,  and  by  availing  himself  of  these 
currents,  he  may  reach  the  Pole  and  return  to  his  ship,  or 
so  near  as  to  be  able  to  reach  it  by  traveling  over  the  ice 
in  light  sledges  that  will  be  carried  for  that  purpose.  In 
making  any  estimate  of  the  risk  of  Arctic  aerostation,  we 
must  banish  from  our  minds  the  preconceptions  induced  by 
our  British  experience  of  the  uncertainties  of  the  wind,  and 
only  consider  the  atmospheric  actualities  of  the  Polar  re- 
gions, so  far  as  we  know  them. 

Let  us  now  consider  the  second  danger,  viz.,  that  of  being 
blown  out  to  sea  and  there  remaining  until  the  leakage  of 
gas  has  destroyed  the  ascending  power  of  the  balloon,  or 
till  the  stock  of  food  is  consumed.  A  glance  at  a  map  of 
the  world  will  show  how  much  smaller  is  the  danger  to  the 
aeronaut  who  starts  from  the  head  of  Baffin's  Bay  than  that 
which  was  incurred  by  those  who  started  from  Vuuxhall  in 
the  Nassau  balloon,  or  by  Captain  Eoher,  who  started  from 
Paris.  Both  of  these  had  the  whole  breadth  of  the  Atlantic 
on  the  W.  and  S.W.,  and  the  North  Sea  and  Arctic  Ocean 
N,  and  N.B.  The  Arctic  balloon,  starting  from  Smith's 
Sound  or  thereabouts,  with  a  wind  from  the  South  (and 
without  such  a  wind  the  start  would  not,  of  course,  be  made), 
would,  if  the  wind  continued  in  the  same  direction,  reach 
the  Pole  in  a  few  hours;  in  seven  or  eight  hours  at  Roller's 


ARCTIC  REGIONS— AERIAL  EXPLORATIONS.     177 

speed;  in  fourteen  or  fifteen  hours  at  the  average  rate  made 
by  the  Nassau  balloon  in  a  "  moderate  breeze."  Now  look 
again  at  the  map  and  see  what  surrounds  them.  Simply 
the  continents  of  Europe,  Asia,  and  America,  by  which  the 
circumpolar  area  is  nearly  land-locked,  with  only  two  outlets, 
that  between  Norway  and  Greenland  on  one  side,  and  the 
narrow  channel  of  Behring's  Straits  on  the  other.  The 
wider  of  these  is  broken  by  Spitzbergen  and  Iceland,  both 
inhabited  islands,  where  a  balloon  may  descend  and  the 
aeronauts  be  hospitably  received.  Taking  the  360  degrees 
of  the  zone  between  the  70th  parallel  of  latitude  and  the 
Arctic  circle,  320  are  land-locked  and  only  40  open  to  the 
sea;  therefore  the  chances  of  coming  upon  land  at  any  one 
part  of  this  zone  is  as  320  to  40;  but  with  a  choice  of  points 
for  descent  such  as  the  aeronauts  would  have  unless  the 
wind  blew  precisely  down  the  axis  of  the  opening,  the 
chances  would  be  far  greater.  If  the  wind  continued  as  at 
starting,  they  would  be  blown  to  Finland;  a  westerly  deflec- 
tion would  land  them  in  Siberia,  easterly  in  Norway;  a 
strong  E.  wind  at  the  later  stage  of  the  trip  would  blow 
them  back  to  Greenland. 

In  all  the  above  I  have  supposed  the  aeronauts  to  be 
quite  helpless,  merely  drifting  at  random  with  that  portion 
of  the  atmosphere  in  which  they  happened  to  be  immersed. 
This,  however,  need  not  be  the  case.  Within  certain  limits 
they  have  a  choice  of  winds,  owing  to  the  prevalence  of 
upper  and  lower  currents  blowing  in  different  and  even  in 
opposite  directions.  Suppose,  for  example,  they  find  them- 
selves N.  of  Spitzbergen,where  "  Parry's  furthest"  is  marked 
on  some  of  our  maps,  and  that  the  wind  is  from  the  N.E.> 
blowing  them  towards  the  Atlantic  opening.  They  would 
then  ascend  or  descend  in  search  of  a  due  N.  or  N.  by  W. 
wind  that  would  blow  them  to  Norway,  or  W.N.W.  to 
Finland,  or  N.W.  to  Siberia,  or  due  E.  back  to  Greenland, 
from  whence  they  might  rejoin  their  ships.  One  or  other 
of  these  would  almost  certainly  be  found.  A  little  may  be 
done  in  steering  a  balloon,  but  so  very  little  that  small 
reliance  should  be  placed  upon  it.  Only  in  a  very  light 
wind  would  it  have  a  sensible  effect,  though  in  case  of  a 
"near  shave"  between  landing,  say  at  the  Lofodens  or 


178  SCIENCE  IN  SHORT  CHAPTERS. 

Iceland,  and  being  blown  out  to  sea,  it  might  just  save 
them. 

As  already  stated,  Commander  Cheyne  believes  in  the 
possibility  of  returning  to  the  ship,  and  bases  his  belief  on 
the  experiments  he  made  from  winter  quarters  in  Northum- 
berland Sound,  where  he  inflated  four  balloons,  attached  to 
them  proportionately  different  weights,  and  sent  them  up 
simultaneously.  They  were  borne  by  diverse  currents  of 
air  in  'four  different  directions  according  to  the  different  atti- 
tudes',™. ,  N.  W. ,  N.  E. ,  S.  E. ,  and  S.  W. , "  thus  proving  that 
in  this  case  balloons  could  be  sent  in  any  required  direction 
by  ascending  to  the  requisite  altitude.  The  war  balloon 
experiments  at  Woolwich  afford  a  practical  confirmation  of 
this  important  feature  in  aeorstation."  Cheyne  proposes  that 
one  at  least  of  the  three  balloons  shall  be  a  rover  to  cross 
the  unknown  area,  and  has  been  called  a  madman  for 
suggesting  this  merely  as  an  alternative  or  secondary  route. 
I  am  still  more  lunatic,  for  I  strongly  hold  the  opinion  that 
the  easiest  way  for  him  to  return  to  his  ship  will  be  to  drift 
rapidly  across  to  the  first  available  inhabited  land,  thence 
come  to  England,  and  sail  in  another  ship  to  rejoin  his 
messmates;  carrying  with  him  his  bird's-eye  chart,  that  will 
demonstrate  once  for  all  the  possibility  or  impossibility  of 
circumnavigating  Greenland,  or  of  sailing,  or  sledging,  or 
walking  to  the  Pole. 

The  worst  dilemma  would  be  that  presented  by  a  dead 
calm,  and  it  is  not  improbable  that  around  the  Pole  there 
may  be  a  region  of  calms  similar  to  that  about  the  Equator. 
Then  the  feather-paddle  or  other  locomotive  device  worked 
by  man-power  would  be  indispensable.  Better  data  than 
we  at  present  possess  are  needed  in  order  to  tell  accurately 
what  may  thus  be  done.  Putting  various  estimates  one 
against  the  other,  it  appears  likely  that  five  miles  an  hour 
may  be  made.  Taking  turn  and  turn  about,  two  or  three 
aeronauts  could  thus  travel  fully  100  miles  per  day,  and 
return  from  the  Pole  to  the  ship  in  less  than  five  days. 

Or  take  the  improbable  case  of  a  circular  wind  blowing 
round  the  Pole,  as  some  have  imagined.  This  would  simply 
demand  the  working  of  the  paddle  always  northwards  in 
going  to  the  Pole,  and  always  southwards  in  returning.  The 


ARCTIC  REGIONS—  AERIAL  EXPLORATIONS.     179 

resultant  would  be  a  spiral  course  winding  inwards  in  the 
first  case,  and  outwards  in  the  second.  The  northward  or 
southward  progress  would  be  just  the  same  as  in  a  calm  if 
the  wind  were  truly  concentric  to  the  Pole.  Some  rough 
approximation  to  such  currents  may  exist,  and  might  be 
dealt  with  on  this  principle. 

Let  us  now  consider  the  third  danger,  that  of  the  dark- 
ness. The  seriousness  of  this  may  be  inferred  from  the 
following  description  of  the  journey  of  the  Nassau  balloon, 
published  at  the  time :  "  It  seemed  to  the  aeronauts  as  if  they 
were  cleaving  their  way  through  an  interminable  mass  of 
black  marble  in  which  they  were  imbedded,  and  which, 
solid  a  few  inches  before  them,  seemed  to  soften  as  they 
approached  in  order  to  admit,  them  still  further  within  its 
cold  and  dusky  enclosure.  In  this  way  they  proceeded 
blindly,  as  it  may  well  be  called,  until  about  3. 30  A.M.,  when 
in  the  midst  of  the  impenetrable  darkness  and  profound 
stillness  an  unusual  explosion  issued  from  the  machine 
above,  followed  by  a  violent  rustling  of  the  silk,  and  all  the 
signs  which  might  be  supposed  to  accompany  the  bursting 
of  the  balloon.  The  car  was  violently  shaken.  A  second 
and  a  third  explosion  followed  in  quick  succession.  The 
danger  seemed  immediate,  when  suddenly  the  balloon 
recovered  her  usual  form  and  stillness.  These  alarming 
symptoms  seemed  to  have  been  produced  by  collapsing^  of 
the  balloon  under  the  diminished  temperature  of  the  upper 
regions  after  sunset,  and  the  silk  forming  into  folds  under 
the  netting.  Now,  when  the  guide  rope  informed  the  voy- 
agers that  the  balloon  was  too  near  the  earth,  ballast  was 
thrown  out,  and  the  balloon  rising  rapidly  into  a  thinner 
air  experienced  a  diminution  of  pressure,  and  consequent 
expansion  of  the  gas. 

"  The  cold  during  the  night  ranged  from  a  few  degrees 
below  to  the  freezing  point.  As  morning  advanced  the 
rushing  of  waters  was  heard,  and  so  little  were  the  aeronauts 
aware  of  the  course  which  they  had  been  pursuing  during 
the  night,  that  they  supposed  themselves  to  have  been 
thrown  back  upon  the  shores  of  the  German  Ocean,  or 
about  to  enter  the  Baltic,  whereas  they  were  actually  over 
the  Rhine,  not  far  from  Coblentz." 


180  SCIENCE  IN  SHOUT  CHAPTERS. 

All  this  blind  drifting  for  hours,  during  which  the  bal- 
loon may  be'  carried  out  to  sea,  and  opportunities  of  safe 
descent  may  be  lost,  is  averted  in  an  Arctic  balloon  voyage, 
which  would  be  made  in  the  summer,  when  the  sun  never 
sets.  There  need  be  no  break  in  the  survey  of  the  ground 
passed  over,  no  difficulty  in  pricking  upon  a  chart  the  course 
taken  and  the  present  position  at  any  moment.  With  an 
horizon  of  50  to  100  miles'  radius  the  approach  of  such  a 
danger  as  drifting  to  the  open  ocean  would  be  perceived 
in  ample  time  for  descent,  and  as  a  glance  at  the  map  will 
show,  this  danger  cannot  occur  until  reaching  the  latitudes 
of  inhabited  regions. 

The  Arctic  aeronauts  will  have  another  great  advantage 
over  those  who  ascend  from 'any  part  of  England.  They 
can  freely  avail  themselves  of  Mr.  Green's  simple  but  most 
important  practical  invention — the  drag-rope.  This  is  a 
long  and  rather  heavy  rope  trailing  on  the  ground.  It  per- 
forms two  important  functions.  First,  it  checks  the  pro- 
gress of  the  balloon,  causing  it  to  move  less  rapidly  than 
the  air  in  which  it  is  immersed.  The  aeronaut  thus  gets  a 
slight  breeze  equivalent  to  the  difference  between  the  velo- 
city of  the  wind  and  that  of  the  balloon's  progress.  He 
may  use  this  as  a  fulcrum  to  effect  a  modicum  of  steerage. 

The  second  and  still  more  important  use  of  the  drag-rope 
is  the  very  great  economy  of  ballast  it  achieves.  Suppose 
the  rope  to  be  1000  feet  long,  its  weight  equal  to  1  Ib.  for 
every  ten  feet,  and  the  balloon  to  have  an  ascending  power 
of  50  Ibs.  It  is  evident  that  under  these  conditions  the 
balloon  will  retain  a  constant  elevation  of  500  feet  above 
the  ground  below  it,  and  that  500  feet  of  rope  will  trail 
upon  the  ground.  Thus,  if  a  mountain  is  reached  no  bal- 
last need  be  thrown  away  in  order  to  clear  the  summit,  as 
the  balloon  will  always  lift  its  500  feet  of  rope,  and  thus 
always  rise  with  the  up-slope  and  descend  with  the  down- 
slope  of  hill  and  dale.  The  full  use  of  this  simple  and 
valuable  adjunct  to  aerial  traveling  is  prevented  in  such  a 
country  as  ours  by  the  damage  it  might  do  below,  and  the 
temptation  it  affords  to  mischievous  idiots  near  whom  it 
may  pass. 

In  the  course  of  many  conversations  with  various  people 


ARCTIC  REGIONS— AERIAL  EXPLORATIONS.      181 

on  this  subject  I  have  been  surprised  at  the  number  of  edu- 
cated men  and  women  who  have  anticipated  with  something 
like  a  shudder  the  terrible  cold  to  which  the  poor  aeronauts 
will  be  exposed. 

This  popular  delusion  which  pictures  the  Arctic  regions 
as  the  abode  of  perpetual  freezing,  is  so  prevalent  and 
general,  that  some  explanation  is  demanded. 

The  special  characteristic  of  Arctic  climate  is  a  cold  and 
long  winter  and  a  short  and  hot  summer.  The  winter  is 
intensely  cold  simply  because  the  sun  never  shines,  and 
the  summer  is  very  hot  because  the  sun  is  always  above  the 
horizon,  and,  unless  hidden  by  clouds  or  mist,  is  continu- 
ally shining.  The  summer  heat  of  Siberia  is  intense,  and 
the  vegetable  proportionately  luxuriant.  I  have  walked 
over  a  few  thousand  miles  in  the  sunny  South,  but  never 
was  more  oppressed  with  the  heat  than  in  walking  up  the 
Tromsdal  to  visit  an  encampment  of  Laplanders  in  the 
summer  of  1856. 

On  the  17th  July  I  noted  the  temperature  on  board  the 
steam  packet  when  we  were  about  three  degrees  north  of 
the  Arctic  circle.  It  stood  at  77°  well  shaded  in  a  saloon 
under  the  deck;  it  was  92°  in  the  "  rok  lugar,"  a  little 
smoking  saloon  built  on  deck;  and  108°  in  the  sun  on  deck. 
This  was  out  at  sea,  where  the  heat  was  less  oppressive  than 
on  shore.  The  summers  of  Arctic  Norway  are  very  variable 
on  account  of  the  occasional  prevalence  of  misty  weather. 
The  balloon  would  be  above  much  of  the  mist,  and  would 
probably  enjoy  a  more  equable  temperature  during  the 
twenty-four  hours  than  in  any  part  of  the  world  where  the 
sun  sets  at  night. 

I  am  aware  that  the  above  is  not  in  accordance  with  the 
experience  of  the  Arctic  explorers  who  have  summered  in 
such  places  as  Smith's  Sound.  I  am  now  about  to  per- 
petrate something  like  a  heresy  by  maintaining  that  the 
summer  climate  there  experienced  by  these  explorers  is 
quite  exceptional,  is  not  due  to  the  latitude,  but  to  causes 
that  have  hitherto  escaped  the  notice  of  the  explorers  them- 
selves and  of  physical  geographers  generally.  The  following 
explanation  will  probably  render  my  view  of  this  subject 
intelligible: 


182  SCIENCE  IN  SHORT  CHAPTERS. 

As  already  stated,  the  barrier  fringe  that  has  stopped  the 
progress  of  Arctic  explorers  is  a  broken  mountainous  shore 
down  which  is  pouring  a  multitude  of  glaciers  into  the  sea. 
The  ice  of  these  glaciers  is,  of  course,  fresh-water  ice.  Now, 
we  know  that  when  ice  is  mixed  with  salt  water  we  obtain 
what  is  called  "a,  freezing  mixture" — a  reduction  of  tem- 
perature far  below  the  freezing  point,  due  to  the  absorption 
of  heat  by  the  liquefaction  of  the  ice.  Thus  the  heat  of 
the  continuously  shining  summer  sun  at  this  particular 
part  of  the  Arctic  region  is  continuously  absorbed  by  this 
powerful  action,  and  a  severity  quite  exceptional  is  thereby 
produced  Every  observant  tourist  who  has  crossed  an 
Alpine  glacier  on  a  hot  summer  day  has  felt  the  sudden 
change  of  climate  that  he  encounters  on  stepping  from 
terra  firma  on  to  the  ice,  and  in  which  he  remains  immersed 
as  long  as  he  is  on  the  glacier.  How  much  greater  must 
be  this  depression  of  temperature  where  the  glacier  ice  is 
broken  up  and  is  floating  in  sea-water,  to  produce  a  vast 
area  of  freezing  mixture,  which  would  speedily  bring  the 
hottest  blasts  from  the  Sahara  down  to  many  degrees  below 
the  freezing  point. 

A  similar  cause  retards  the  beginning  of  summer  in  Arctic 
Norway  and  in  Finland  and  Siberia.  So  long  as  the  winter 
snow  remains  unmelted,  i.e.,  till  about  the  middle  or  end 
of  June,  the  air  is  kept  cold,  all  the  solar  heat  being  ex- 
pended in  the  work  of  thawing.  This  work  finished,  then 
the  warming  power  of  a  non-setting  sun  becomes  evident, 
and  the  continuously  accumulating  heat  of  his  rays  displays 
its  remarkable  effect  on  vegetable  life,  and  everything  cap- 
able of  being  warmed.  These  peculiarities  of  Arctic  climate 
must  become  exaggerated  as  the  Pole  is  approached,  the 
winter  cold  still  more  intense,  and  the  accumulation  of 
summer  heat  still  greater.  In  the  neighborhood  of  the 
North  Gape,  where  these  contrasts  astonish  English  visitors, 
where  inland  summer  traveling  becomes  intolerable  on  ac- 
count of  the  clouds  of  mosquitoes,  the  continuous  sunshine 
only  lasts  from  May  11  to  August  1.  At  the  North  Pole 
the  sun  would  visibly  remain  above  the  horizon  during  about 
seven  months — from  the  first  week  in  March  to  the  first 
week  in  October  (this  includes  the  effect  of  refraction  and 


ARCTIC  REGIONS— AERIAL  EXPLORATIONS.      183 

the  prolonged  summer  of  the  northern  hemisphere  due  to 
the  eccentricity  of  the  earth's  orbit). 

This  continuance  of  sunshine,  in  spite  of  the  moderate 
altitude  of  the  solar  orb,  may  produce  a  very  genial  summer 
climate  at  the  Pole.  I  say  "may,"  because  mere  latitude 
is  only  one  of  the  elements  of  climate,  especially  in  high 
latitudes.  Very  much  depends  upon  surface  configuration 
and  the  distribution  of  land  and  water.  The  region  in 
which  our  Arctic  expedition  ships  have  been  ice-bound 
combines  all  the  most  unfavorable  conditions  of  Arctic 
summer  climate.  It  is  extremely  improbable  that  those 
conditions  are  maintained  all  the  way  to  the  Pole.  We 
know  the  configuration  of  Arctic  Europe  and  Arctic  Asia, 
that  they  are  masses  of  land  spreading  out  northward  round 
the  Arctic  circle  and  narrowing  southward  to  angular  ter- 
minations. The  southward  configuration  and  northward 
outspreading  of  North  America  are  the  same,  but  we  can- 
not follow  the  northern  portion  to  its  boundary  as  we  may 
that  of  Europe  and  Asia,  both  of  which  terminate  in  an 
Arctic  Ocean.  Greenland  is  remarkably  like  Scandinavia; 
Davis's  Strait,  Baffin's  Bay,  and  Smith's  Sound  correspond- 
ing with  the  Baltic  and  the  Gulf  of  Bothnia.  The  deep 
fjords  of  Greenland,  like  those  of  Scandinavia,  are  on  its 
western  side,  and  the  present  condition  of  Greenland  cor- 
responds to  that  of  Norway  during  the  milder  period  of  the 
last  glacial  epoch.  If  the  analogy  is  maintained  a  little 
further  north  than  our  explorers  have  yet  reached  we  must 
come  upon  a  Polar  sea,  just  as  we  come  upon  the  White 
Sea  and  the  open  Arctic  Ocean  if  we  simply  travel  between 
400  and  500  miles  due  north  from  the  head  of  the  frozen 
Gulf  of  Bothnia. 

Such  a  sea,  if  unencumbered  with  land  ice,  will  supply 
the  most  favorable  conditions  for  a  genial  arctic  summer, 
especially  if  it  be  dotted  with  islands  of  moderate  elevation, 
which  the  analogies  of  the  known  surroundings  render  so 
very  probable.  Such  islands  may  be  inhabited  by  people 
who  cannot  reach  us  on  account  of  the  barrier  wall  that  has 
hitherto  prevented  us  from  discovering  them.  Some  have 
even  supposed  that  a  Norwegian  colony  is  there  imprisoned. 
Certainly  the  early  colonists  of  Greenland  have  disappeared, 


184  SCIENCE  IN  SHORT  CHAPTERS. 

and  their  disappearance  remains  unexplained.  They  may 
have  wandered  northwards,  mingled  with  the  Esquimaux, 
and  have  left  descendants  in  this  unknown  world.  If  any 
of  Franklin's  crew  crawled  far  enough  they  may  still  be 
with  them,  unable  to  return. 

In  reference  to  these  possibilities  it  should  be  noted  that 
a  barrier  fringe  of  mountainous  land  like  that  of  Green- 
land and  arctic  America  would  act  as  a  condensing  ground 
upon  the  warm  air  flowing  from  the  south,  and  would  there 
accumulate  the  heavy  snows  and  consequent  glaciers,  just 
as  our  western  hills  take  so  much  of  the  rain  from  the 
vapor-laden  winds  of  the  Atlantic.  The  snowfall  imme- 
diately round  the  Pole  would  thus  be  moderated,  and  the 
summer  begin  so  much  earlier. 

I  have  already  referred  to  the  physical  resemblances  of 
Baffin's  Bay,  Smith's  Sound,  etc.,  to  the  Baltic,  the  Gulf 
of  Bothnia,  and  Gulf  of  Finland.  These  are  frozen  every 
winter,  but  the  Arctic  Ocean  due  north  of  them  is  open  all 
the  winter,  and  every  winter.  The  hardy  Norse  fishermen 
are  gathering  their  chief  harvest  of  cod  fish  in  the  open  sea 
around  and  beyond  the  North  Cape,  Nordkyn,  etc.,  at  the 
very  time  when  the  Russian  fleet  is  hopelessly  frozen  up  in 
the  Gulf  of  Finland.  But  how  far  due  north  of  this  frozen 
Baltic  are  these  open-sea  fishing  banks?  More  than  14 
degrees — more  than  double  the  distance  that  lies  between 
the  winter  quarters  of  some  of  our  ships  in  Smith's  Sound 
and  the  Pole  itself.  This  proves  how  greatly  physical 
configuration  and  oceanic  communication  may  oppose  the 
climatic  influences  of  mere  latitude.  If  the  analogy  be- 
tween Baffin's  Bay  and  the  Baltic  is  complete,  a  Polar  sea 
will  be  found  that  is  open  in  the  summer  at  least. 

On  the  other  hand,  it  may  be  that  ranges  of  mountains 
covered  with  perpetual  snow,  and  valleys  piled  up  with 
hiige  glacial  accumulations,  extend  all  the  way  to  the  Pole, 
and  thus  give  to  our  globe  an  arctic  ice-cap  like  that  dis- 
played on  the  planet  Mars.  This,  however,  is  very  im- 
probable, for,  if  it  were  the  case,  we  ought  to  find  a  circum- 
polar  ice-wall  like  that  of  the  antarctic  regions;  the  Arctic 
Ocean  beyond  the  North  Cape  should  be  crowded  with  ice- 
bergs instead  of  being  open  and  iceless  all  the  year  round. 


ARCTIC  REGIONS-AERIAL  EXPLORATIONS.      185 

With  such  a  configuration  the  ice-wall  should  reach  Spitz- 
bergen  and  stretch  across  to  Nova  Zembla;  but,  instead  of 
this,  we  have  there  such  an  open  stretch  of  arctic  water, 
that  in  the  summer  of  1§76  Captain  Kjelsen,  of  Tromso, 
sailed  in  a  whaler  to  lat.  81°  30'  without  sighting  ice.  He 
was  then  but  510  geographical  miles  from  the  Pole,  with 
open  sea  right  away  to  his  north  horizon,  and  nobody  can 
say  how  much  farther. 

These  problems  may  all  be  solved  by  the  proposed  expedi- 
tion. The  men  are  ready  and  willing;  one  volunteer  has 
even  promised  1000Z.  on  condition  that  he  shall  be  allowed 
to  have  a  seat  in  one  of  the  balloons.  All  that  is  wanted 
are  the  necessary  funds,  and  the  amount  required  is  but  a 
small  fraction  of  what  is  annually  expended  at  our  race- 
courses upon  villainous  concoctions  of  carbonic  acid  and 
methylated  cider  bearing  the  name  of  "  champagne." 

Arrangements  are  being  made  to  start  next  May,  but  in 
the  meantime  many  preliminary  experiments  are  required. 
One  of  these,  concerning  which  I  have  been  boring  Com- 
mander Chefne  and  the  committee,  is  a  thorough  and 
practical  trial  of  the  staying  properties  of  hydrogen  gas 
when  confined  in  given  silken  or  other  fabrics  saturated 
with  given  varnishes.  We  are  still  ignorant  on  this  funda- 
mental point.  We  know  something  about  coal-gas,  but 
little  or  nothing  of  the  hydrogen,  such  as  may  be  used  in 
the  foregoing  expedition.  Its  exosmosis,  as  proved  by 
Graham,  depends  upon  its  adhesion  to  the  surface  of  the 
substance  confining  it.  Every  gas  has  its  own  speciality  in 
this  respect,  and  a  membrane  that  confines  a  hydrocarbon 
like  coal-gas  may  be  very  unsuitable  for  pure  hydrogen,  or 
vice  versd.  Hydrogen  passes  through  hard  steel,  carbonic 
oxide  through  red-hot  iron  plates,  and  so  on  with  other 
gases.  They  are  guilty  of  most  improbable  proceedings  in 
the  matter  of  penetrating  apparently  impenetrable  sub- 
stances. 

The  safety  of  the  aeronaufs  and  the  success  of  the  aerial 
exploration  primarily  depends  upon  the  length  of  time  that 
the  balloons  can  be  kept  afloat  in  the  air. 

A  sort  of  humanitarian  cry  ha  sbeen  raised  against  this 
expedition,  on  the  ground  that  unnaturally  good  people 


186  SCIENCE  IN  SHORT  CHAPTERS. 

(of  whom  we  now  meet  so  many)  should  not  be  guilty  of 
aiding  and  abetting  a  scheme  that  may  cause  the  sacrifice 
of  human  life.  These  kind  friends  may  be  assured  that,  in 
spite  of  their  scruples,  the  attempt  will  be  made  by  men 
who  share  none  of  their  fears,  unless  the  preliminary  ex- 
periments prove  that  a  balloon  cannot  be  kept  up  long 
enough.  Therefore  the  best  way  to  save  their  lives  is  to 
subscribe  at  once  for  the  preliminary  expense  of  making 
these  trials,  which  will  either  discover  means  of  traveling 
safely,  or  demonstrate  the  impossibility  of  such  ballooning 
altogether.  Such  experiments  will  have  considerable  scien- 
tific value  in  themselves,  and  may  solve  other  problems 
besides  those  of  arctic  exploration. 

Why  not  apply  balloons  to  African  exploration  or  the 
crossing  of  Australia?  The  only  reply  to  this  is  that  we 
know  too  little  of  the  practical  possibilities  of  such  a 
method  of  traveling  when  thus  applied.  Hitherto  the 
balloon  has  only  been  a  sensational  toy.  We  know  well 
enough  that  it  cannot  be  steered  in  a  predetermined  line, 
i.e.,  from  one  point  to  another  given  point^  but  this  is 
quite  a  different  problem  from  sailing  over  a  given  surface 
of  considerable  area.  This  can  be  done  to  a  certain  extent, 
but  we  want  to  know  definitely  to  what  extent,  and  what 
are  the  limits  of  reliability  and  safety.  With  this  knowl- 
edge, and  its  application  by  the  brave  and  skillful  men  who 
are  so  eager  to  start,  the  solution  of  the  Polar  mystery 
assumes  a  new  and  far  more  hopeful  phase  than  it  has  ever 
before  presented. 

THE  ANGLO-AMERICAN  ARCTIC  EXPEDITION. 

Commander  Cheyne  has  gone  to  America  to  seek  the 
modest  equipment  that  his  own  countrymen  are  unable  to 
supply.  He  proposes  now  that  his  expedition  shall  be 
"Anglo-American."  I  have  been  asked  to  join  an  arctic 
council,  to  cooperate  on  this,  side,  and  have  refused  on 
anti-patriotic  grounds.  As  a  member  of  the  former  arctic 
committee,  I  was  so  much  disgusted  with  the  parsimony  of 
our  millionaires  and  the  anti-geographical  conduct  of  the 
Savile  Row  Mutual  Admiration  Society,  that  I  heartily 


ARCTIC  REGIONS—  AERIAL  EXPLORATIONS.      187 

wish  that  in  this  matter  our  American  grandchildren  may 
"lick  the  Britishers  quite  complete."  It  will  do  us  much 
good. 

My  views,  expressed  in  the  f<  Gentleman's  Magazine"  of 
July  1880,  and  repeated  above,  remain  unchanged,  except 
in  the  direction  of  confirmation  and  development.  I  still 
believe  that  an  enthusiastic,  practically  trained,  sturdy  arc- 
tic veteran,  who  has  endured  hardship  both  at  home  and 
abroad,  whose  craving  eagerness  to  reach  the  Pole  amounts 
to  a  positive  monomonia,  who  lives  for  this  object  alone, 
and  is  ready  to  die  for  it,  who  will  work  at  it  purely  for  the 
work's  sake — will  be  the  right  man  in  the  right  place  when 
at  the  head  of  a  modestly  but  efficiently  equipped  Polar  ex- 
pedition, especially  if  Lieutenant  Schwatka  is  his  second 
in  command. 

They  will  not  require  luxurious  saloons,  nor  many  cases 
of  champagne;  they  will  care  but  little  for  amateur  theatri- 
cals; they  will  follow  the  naval  traditions  of  the  old  British 
"sea-dogs"  rather  than  those  of  our  modern  naval  lap- 
dogs,  and  will  not  turn  back  after  a  first  struggle  with  the 
cruel  arctic  ice,  even  though  they  should  suppose  it  to  be 
"paleocrystic." 

MR.  WALTER  POWELL. 

Scientific  aerostation  has  lost  its  most  promising  expert 
by  the  untimely  death  of  Walter  Powell.  He  was  not  a 
mere  sensational  ballooner,  nor  one  of  those  dreamers  who 
imagine  they  can  invent  flying  machines,  or  steer  balloons 
against  the  wind  by  mysterious  electrical  devices  or  by  me- 
chanical paddles,  fan- wheels,  or  rudders. 

He  perfectly  understood  that  a  balloon  is  at  #ie  mercy 
of  atmospheric  currents  and  must  drift  with  them,  but 
nevertheless  he  regarded  it  as  a  most  promising  instrument 
for  geographical  research.  I  had  a  long  conference  with 
him  on  the  subject  in  August  last,  when  he  told  me  that 
the  main  objects  of  the  ascents  he  had  already  made,  and 
should  be  making  for  some  little  time  forward,  were  the 
acquisition  of  practical  skill,  and  of  further  knowledge  of 
atmospheric  currents;  after  which  he  should  make  a  dash 
at  the  Atlantic  with  the  intent  of  crossing  to  America. 


188  SCIENCE  IN  SHORT  CHAPTERS. 

On  my  part,  I  repeated  with  further  argument  what  I 
have  already  urged  on  page  113  of  the  "  Gentleman's  Maga- 
zine" for  July,  1880,  viz.,  the  primary  necessity  of  syste- 
matic experimental  investigation  of  the  rate  of  exosmosis 
(oozing  out)  of  the  gas  from  balloons  made  of  different  ma- 
terials and  variously  varnished. 

Professor  Graham  demonstrated  that  this  molecular  per- 
meation of  gases  and  liquids  through  membranes  mechani- 
cally air-tight,  depends  upon  the  adhesive  affinities  of  par- 
ticular solids  for  other  particular  fluids,  and  these  affinities 
vary  immensely,  their  variations  depending  on  chemical 
differences  rather  than  upon  mechanical  impermeability. 
My  project  to  attach  captive  balloons,  of  small  size  to  the 
roof  of  the  Polytechnic  Institution,  holding  them  by  a  steel- 
yard that  should  indicate  the  pull  due  to  their  ascending 
power,  and  the  rate  of  its  decline  according  to  the  compo- 
sition of  the  membrane,  was  heartily  approved  by  Mr. 
Powell,  and,  had  the  Polytechnic  survived,  would  have 
been  carried  out,  as  it  would  have  served  the  double  pur- 
pose of  scientific  investigation  and  of  sensational  advertise- 
ment for  the  outside  public. 

If  the  aeronaut  were  quite  clear  on  this  point — could 
calculate  accurately  how  long  his  balloon  would  float — he 
might  venture  with  deliberate  calculation  on  journeys  that 
without  such  knowledge  are  mere  exploits  of  blind  daring. 

The  varnishes  at  present  used  are  all  permeable  by  hy- 
drogen gas  and  hydrocarbon  coal-gas,  as  might  be  expected, 
a  priori,  from  the  fact  that  they  are  themselves  solid  hy- 
drocarbons, soluble  in  other  liquid  or  gaseous  hydrocarbons. 
Nothing,  as  far  as  I  can  learn,  has  yet  been  done  with  sil- 
icic or  boracic  varnishes*  which  are  theoretically  imperme- 
able by  Ifydrogen  and  its  carbon  compounds;  but  whether 
they  are  practically  so  under  ballooning  conditions,  and 
can  be  made  sufficiently  pliable  and  continuous,  are  ques- 
tions only  to  be  solved  by  practical  experiments  of  the 


*  Since  the  above  was  written  I  have  made  some  experiments  with 
a  solution  of  shellac  in  borax  (obtained  by  long  boiling),  and  hereby 
claim  the  invention  of  its  application  to  this  purpose,  in  order  to 
prevent  anybody  from  patenting  it.  I  shall  not  do  so  myself. 


THE  LIMITS  OF  OUR  COAL  SUPPLY.  189 

kind  above  named.  Now  that  the  best  man  for  making 
these  experiments  is  gone,  somebody  else  should  undertake 
them.  Unfortunately,  they  must  of  necessity  be  rather 
expensive. 


THE  LIMITS  OF  OUR  COAL  SUPPLY.* 

ESTIMATING  the  actual  consumption  of  coal  for  home 
use  in  Great  Britain  at"  110  millions  of  tons  per  annum,  a 
rise  of  eight  shillings  per  ton  to  consumers  is  equivalent  to 
a  tax  of  44  millions  per  annum.  These  are  the  figures 
taken  by  Sir  William  Armstrong  in  his  address  at  New- 
castle last  February.  As  the  recent  abnormal  rise  in  the 
value  of  coal  has  amounted  to  more  than  this,  consumers 
h'ave  been  paying  at  some  periods  above  a  million  per  week 
as  premium  on  fuel,  even  after  making  fair  deduction  for 
the  rise  of  price  necessarily  due  to  the  diminishing  value 
of  gold. 

Are  we,  the  consumers  of  coal,  to  write  off  all  this  as  a 
dead  loss,  or  have  we  gained  any  immediate  or  prospective 
advantage  that  may  be  deducted  from  the  bad  side  of  the 
account?  I  suspect  that  we  shall  gain  sufficient  to  ulti-> 
mately  balance  the  loss,  and,  even  after  that,  to  leave  some- 
thing on  the  profit  side. 

The  abundance  of  our  fuel  has  engendered  a  shameful 
wastefulness  that  is  curiously  blind  and  inconsistent.  As 
a  typical  example  of  this  inconsistency,  I  may  mention  a 
characteristic  incident.  A  party  of  young  people  were  sit- 
ting at  supper  in  the  house  of  a  colliery  manager.  Among 
them  was  the  vicar  of  the  parish,  a  very  jovial  and  genial 
man,  but  most  earnest  withal  in  his  vocation.  Jokes  and 
banterings  were  freely  flung  across  the  table,  and  no  one 
enjoyed  the  fun  more  heartily  than  the  vicar;  but  presently 
one  unwary  youth  threw  a  fragment  of  bread-crust  at  his 
opposite  neighbor,  and  thus  provoked  retaliation.  The 
countenance  of  the  vicar  suddenly  changed,  and  in  stern 

*  Written  during  the  coal  famine  of  1872-73. 


190  SCIENCE  IN  SHORT  CHAPTERS. 

clerical  tones  he  rebuked  the  wickedness  of  thus  wasting 
the  bounties  of  the  Almighty.  A  general  silence  foil  owed, 
and  a  general  sense  of  guilt  prevailed  among  the  revellers. 
At  the  same  time,  and  in  the  same  room,  a  blazing  fire,  in 
an  ill-constructed  open  fire-place,  was  glaring  reproachfully 
at  all  the  guests,  but  no  one  heeded  the  immeasurably 
greater  and  utterly  irreparable  waste  that  was  there  pro- 
ceeding. To  every  unit  of  heat  that  was  fully  utilized  in 
warming  the  room,  there  were  eight  or  nine  passing  up  the 
chimney  to  waste  their  energies  upon  the  senseless  clouds 
and  boundless  outer  atmosphere.  A  large  proportion  of 
the  vicar's  parishioners  are  colliers,  in  whose  cottages  huge 
fires  blaze  most  wastefully  all  day,  and  are  left  to  burn  all 
night  to  save  the  trouble  of  re-lighting.  The  vicar  dili- 
gently visits  these  cottages,  and  freely  admonishes  where 
he  deems  it  necessary;  yet  he  sees  in  this  general  waste  of 
coal  no  corresponding  sinfulness  to  that  of  wasting  bread. 
Why  is  he  so  blind  in  one  direction,  while  his  moral  vision 
is  so  microscopic  in  the  other?  Why  are  nearly  all  Eng- 
lishmen and  Englishwomen  as  inconsistent  as  the  vicar  m 
this  respect? 

There  are  doubtless  several  combining  reasons  for  this, 
but  I  suspect  that  the  principal  one  is  the  profound  im- 
pression which  we  have  inherited  from  the  experience  and 
traditions  of  the  horrors  of  bread-famine.  A  score  of 
proverbs  express  the  important  practical  truth  that  we 
rarely  appreciate  any  of  our  customary  blessings  until  we 
have' tasted  the  misery  of  losing  them.  Englishmen  have 
tasted  the  consequences  of  approximate  exhaustion  of  the 
national  grain  store,  but  have  never  been  near  to  the  ex- 
haustion of  the  national  supply  of  coal. 

I  therefore  maintain  most  seriously  that  we  need  a  severe 
coal  famine,  and  if  all  the  colliers  of  the  United  Kingdom 
were  to  combine  for  a  simultaneous  winter  strike  of  about 
three  or  six  months'  duration,  they  might  justly  be  re- 
garded as  unconscious  patriotic  martyrs,  like  soldiers  slain 
upon  a  battle-field.  The  evils  of  such  a  thorough  famine 
would  be  very  sharp,  and  proportionally  beneficent,  but 
only  temporary;  there  would  not  be  time  enough  for 
manufacturing  rivals  to  sink  pits,  and  at  once  erect  com- 


THE  LIMITS  OF  OUR  COAL  SUPPLY.  191 

peting  iron-works  ;  but  the  whole  world  would  partake  of 
our  calamity,  and  the  attention  of  all  mankind  would  be 
aroused  to  the  sinfulness  of  wasting  coal.  Six  months  of 
compulsory  wood  and  peat  fuel,  with  total  stoppage  of  iron 
supplies,  would  convince  the  people  of  these  islands  that 
waste  of  coal  is  even  more  sinful  than  waste  of  bread, — 
would  lead  us  to  reflect  on  the  fact  that  our  stock  of  coal 
is  a  definite  and  limited  quantity  that  was  placed  in  the 
present  storehouse  long  before  human  beings  came  upon 
the  earth  ;  that  every  ton  of  coal  that  is  wasted  is  lost  for 
ever,  and  cannot  be  replaced  by  any  human  -effort,  while 
bread  is  a  product  of  human  industry,  and  its  waste  may 
be  replaced  by  additional  human  labor ;  that  the  sin  of 
bread-wasting  does  admit  of  agricultural  atonement,  while 
there  is  no  form  of  practical  repentance  that  can  positively 
and  directly  replace  a  hundredweight  of  wasted  coal. 

Nothing  short  of  the  practical  and  impressive  lesson  of 
bitter  want  is  likely  to  drive  from  our  households  that 
wretched  fetish  of  British  adoration,  the  open  "English- 
man's fireside."  Eeason  seems  powerless  against  the  super- 
stition of  this  form  of  fire-worship.  Tell  one  of  the 
idolaters  that  his  household  god  is  wasteful  and  extravagant, 
that  five-sixths  of  the  heat  from  his  coal  goes  up  the 
chimney,  and  he  replies,  "  I  don't  care  if  it  does ;  I  can 
afford  to  pay  for  it.  I  like  to  see  the  fire,  and  have  the 
right  to  waste  what  is  my  own."  Tell  him  that  healthful 
ventilation  is  impossible  while  the  lower  part  of  a  room 
opens  widely  into  a  heated  shaft,  that  forces  currents  of 
cold  air  through  doors  and  Avindow  leakages,  which  unite 
to  form  a  perpetual  chilbrain  stratum  on  the  floor,  and 
leaves  all  above  the  mantel-piece  comparatively  stagnant. 
Tell  him  that  no  such  things  as  "draughts"  should  exist 
in  a  properly  warmed  and  ventilated  house,  and  that  even 
with  a  thermometer  at  zero  outside,  every  part  of  a  well- 
ordered  apartment  should  be  equally  habitable,  instead  of 
merely  a  semicircle  about  the  hearth  of  the  fire-worshiper  ; 
he  shuts  his  ears,  locks  up  his  understanding,  because  his 
grandfather  and  grandmother  believed  that  the  open- 
mouthed  chimney  was  the  one  and  only  true  English  means 
of  ventilation. 


192  SCIENCE  IN  SH(fRT  CHAPTERS. 

But  suppose  we  were  to  say,  "You  love  a  cheerful  blaze, 
can  afford  to  pay  for  it,  and  therefore  care  not  how  much 
coal  you  waste  in  obtaining  it.  We  also  loye  a  cheerful 
blaze,  but  have  a  great  aversion  to  coal-smoke  and  tarry 
vapors ;  and  we  find  that  we  can  make  a  beautiful  fire, 
quite  inoffensive  even  in  the  middle  of  the  room,  provided 
we  feed  it  with  stale  quartern  loaves.  We  know  that  such 
fuel  is  expensive,  but  can  afford  to  pay  for  it,  and  choose 
to  do  so."  Would  he  not  be  shocked  at  the  sight  of  the 
blazing  loaves,  if  this  extravagance' were  carried  out  ? 

This  popular  inconsistency  of  disregarding  the  waste  of 
a  valuable  and  necessary  commodity,  of  which  the  supply 
is  limited  and  unrenewable,  while  we  have  such  proper 
horror  of  wilfully  wasting  another  similar  commodity  which 
can  be  annually  replaced  as  long  as  man  remains  in  living 
contact  with  the  earth,  will  gradually  pass  away  when 
rational  attention  is  directed  to  the  subject.  If  the  recent 
very  mild  suggestion  of  a  coal-famine  does  something 
towards  placing  coal  on  a  similar  pedestal  of  popular  venera- 
tion to  that  which  is  held  by  the  "  staff  of  life,"  the  million 
a  week  that  it  has  cost  the  coal  consumer  will  have  been 
profitably  invested. 

Many  who  were  formerly  deaf  to  the  exhortations  of  fuel 
economists  are  now  beginning  to  listen.  "Forty  shillings 
per  ton "  has  acted  like  an  incantation  upon  the  spirit  of 
Count  Eumford.  After  an  oblivion  of  more  than  eighty 
years,  his  practical  lessons  have  again  sprung  up  among  us. 
Some  are  already  inquiring  how  he  managed  to  roast  112 
Ibs.  of  beef  at  the  Foundling  Hospital  with  22  Ibs.  of  coal, 
and  to  use  the  residual  heat  for  cooking  the  potatoes,  and 
why  it  is  that  with  all  our  boasted  progress  we  do  not  now 
in  the  latter  third  of  the  nineteenth  century,  repeat  that 
which  he  did  in  the  eighteenth. 

The  fact  that  the  consumption  of  coal  in  London  during 
the  first  four  months  of  1873  has,  in  spite  of  increasing 
population,  amounted  to  49,707  tons  less  than  the  corre- 
sponding period  of  1872,  shows  that  some  feeble  attempts 
have  been  made  to  economize  the  domestic  consumption  of 
fuel.  One  very  useful  result  of  the  recent  scarcity  of  coal 
has  been  the  awakening  of  a  considerable  amount  of  general 


THE  LIMITS  OF  OUR  COAL  SUPPLY.  193 

interest  in  the  work  of  stock-taking,  a  tedious  process 
which  improvident  people  are  too  apt  to  skirk,  but  which 
is  quite  indispensable  to  sound  business  proceedings,  either 
of  individuals  or  nations. 

There  are  many  discrepancies  in  the  estimates  that  have 
been  made  of  the  total  available  quantity  of  British  coal. 
The  speculative  nature  of  some  of  the  data  renders  this 
inevitable,  but  all  authorities  appear  to  agree  on  one  point, 
viz.,  that  the  amount  of  our  supplies  will  not  be  determined 
by  the  actual  total  quantity  of  coal  under  our  feet,  but  by 
the  possibilities  of  reaching  it.  This  is  doubtless  correct, 
but  how  will  these  possibilities  be  limited,  and  what  is  the 
extent  or  range  of  the  limit?  On  both  these  points  I  ven- 
ture to  disagree  with  the  eminent  men  who  have  so  ably 
discussed  this  question.  First,  as  regards  the  nature  of  the 
limit  or  barrier  that  will  stop  our  further  progress  in  coal- 
getting.  This  is  generally  stated  to  be  the  depth  of  the 
seams.  The  Eoyal  Commissioners  of  1870  based  their 
tables  of  the  quantity  of  available  coal  in  the  visible  and 
concealed  coal-fields  upon  the  assumption  that  4000  feet  is 
the  limit  of  possible  working.  This  limit  is  the  same  that 
was  taken  by  Mr.  Hull  ten  years  earlier.  Mr.  Hull,  in  the 
last  edition  of  "  The  Coal  Fields  of  Great  Britain,"  p.  326, 
referring  to  Professor  Eamsay's  estimate,  says,  "  These 
estimates  are  drawn  up  for  depths  down  to  4000  feet  below 
the  surface,  and  even  beyond  this  limit;  but  with  this  latter 
quantity  it  is  scarcely  necessary  that  we  should  concern  our- 
selves." I  shall  presently  show  reasons  for  believing  that 
the  time  may  ultimately  arrive  when  we  shall  concern  our- 
selves with  this  deep  coal,  and  actually  get  it;  while,  on  the 
other  hand,  that  remote  epoch  will  be  preceded  by  another 
period  of  practical  approximate  exhaustion  of  British  coal 
supply,  which  is  likely  to  arrive  long  before  we  reach  a 
working  depth  of  4000  feet. 

The  Eoyal  Commissioners  estimate  that  within  the  lim- 
its of  4000  feet  we  have  hundreds  of  square  miles  of  attain- 
able coal  capable  of  yielding,  after  deducting  40  per  cent 
for  loss  in  getting,  etc.,  146,480  millions  of  tons;  or,  if  we 
take  this  with  Mr.  Hull's  deduction  of  one-twentieth  for 
seams  under  two  feet  in  thickness,  there  remains  139,000 


1,94  SCIENCE  IN  SHORT  CHAPTERS. 

millions  of  tons,  which,  at  present  rate  of  consumption, 
would  last  about  1200  years.  But  the  rate  of  consumption 
is  annually  increasing,  not  merely  on  account  of  increasing 
population,  but  also  from  the  fact  that  mechanical  inven- 
tions are  perpetually  superseding  hand  labor,  and  the 
source  of  power  in  such  cases. is  usually  derived  from  coal. 
This  consideration  induced  Professor  Jevons,  in  1865,  to 
estimate  that  between  1861  and  1871  the  consumption 
would  increase  from  83,500,000  tons  to  118,000,000  tons. 
Mr.  Hunt's  official  return  for  1871  shows  that  this  estimate 
was  a  close  approximation  to  the  truth,  the  actual  total  for 
1871  having  been.  117,352,028  tons.  At  this  rate  of  an 
arithmetical  increase  of  three  and  a  half  tons  per  annum, 
139,000  millions  of  tons  would  last  but  250  years.  Mr. 
Hull,  taking  the  actual  increase  at  three  millions  of  tons 
per  annum,  extends  it  to  276  years.  Hitherto  the  annual 
increase  has  followed  a  geometrical  rather  than  arithmeti- 
cal progress,  and  those  who  anticipate  a  continuance  of 
this  allow  us  a  much  shorter  lease  of  our  coal  treasures. 
Mr.  Price  Williams  maintains  that  the  increase  will  pro- 
ceed in  a  diminishing  ratio  like  that  of  the  increase  of  pop- 
ulation; and  upon  this  basis  he  has  calculated  that  the 
annual  consumption  will  amount  to  274  millions  of  tons  a 
hundred  years  hence,  and  the  whole  available  stock  of  coal 
will  last  about  360  years. 

The  latest  returns  show,  for  1872,  an  output  of  123,546,- 
758  tons,  which,  compared  with  1871,  gives  a  rate  of  in- 
crease of  more  than  double  the  estimate  of  Mr.  Hull,  and 
indicate  that  prices  have  not.yet  risen  sufficiently  to  check 
the  geometrical  rate  of  increase.*  Mr  Hull  very  justly 
points  out  the  omission  in  those  estimates  which,  do  not 
"take  into  account  the  diminishing  ratio  at  which  coal 
must  be  consumed  when  it  becomes  scarcer  and  more  ex- 
pensive;" but,  on  the  other  hand,  he  omits  the  opposite  in- 
fluence of  increasing  prices  on  production,  which  has  been 
strikingly  illustrated  bjj  the  extraordinary  number  of  new 


*From  1870  to  1880  the  amount  has  risen  from  110,431,192  to  146,- 
818,622  tons  per  annum,  an  average  increase  of  3,638,743  tons  per 

aunum. 


THE  LIMITS  OF  OUR  COAL  SUPPLY.  195 

coal-mining  enterprises  that  hare  been  launched  during  the 
last  six  months.  If  we  continue  as  we  are  now  proceeding, 
a  practical  and  permanent  eoal  famine  will  be  upon  us 
within  the  lifetime  of  many  of  the  present  generation.  By 
such  a  famine,  I  do  not  mean  an  actual  exhaustion  of  our 
coal  seams  (which  will  never  be  effected),  but  such  a  scar- 
city and  rise  of  prices  as  shall  annihilate  the  most  voracious 
of  our  coal-consuming  industries,  those  which  depend  upon 
abundance  of  cheap  coal,  such  as  the  manufacture  of  pig- 
iron,  etc.* 

The  action  of  increasing  prices  has  been  but  lightly  con- 
sidered hitherto,  though  its  importance  is  paramount  in 
determining  the  limits  of  our  coal  supply;  I  even  venture 
so  far  as  to  affirm  that  it  is  not  the  depth  of  the  coal  seams, 
not  the  increasing  temperature  nor  pressure  as  we  proceed 
downwards,  nor  even  thinness  of  seam,  that  will  practically 
determine  the  limits  of  British  coal-getting,  but  simply  the 
price  per  ton  at  the  pit's  month. 

In  proof  of  this,  I  may  appeal  to  actual  practice.  Mr. 
Hull  and  others  have  estimated  the  working  limit  of  thin- 
ness at  two  feet,  and  agree  in  regarding  thinner  seams  than 
this  as  unworkable.  This  is  unquestionably  correct  BO 
long  as  the  getting  is  effected  in  the  usual  manner.  A  col- 
lier cannot  lie  down  and  hew  a  much  thinner  seam  than 
this,  if  he  works  as  colliers  work  at  present.  But  the  lead 
and  copper  miners  succeed  in  working  far  thinner  lode* , 
even  down  to  the  thickness  of  a  few  inches,  and  the  gold- 
digger  crushes  the  hardest  component  of  the  earth's  crust 
to  obtain  barely  visible  grains  of  the  precious  metal.  This 
extension  of  effort  is  entirely  determined  by  market  value. 
At  a  sufficiently  high  price  the  two-feet  limit  of  coal-get- 
ting would  vanish,  and  the  collier  would  work  after  the 
manner  of  the  lead-miner. 


*At  the  present  time  (1882)  we  are  receiving  the  excessive  supplies 
consequent  upon  the  opening  of  new  pits  that,  under  the  stimulus  of 
high  prices,  were  in  the  course  erf  sinking  when  the  above  was  writ- 
ten. Hence  the  present  low  prices.  Presently  the  annual  increase 
of  consumption  will  overtake  this  increased  supply,  and  (mother 
"  coal  famine"  like  that  then  existing  will  follow.  This  is  not  far 
distant. 


196  SCIENCE  IN  SHORT  CHAPTERS. 

We  may  safely  apply  the  same  reasoning  to  the  limits  of 
depth.  The  4000  feet  limit  of  the  Royal  Commissioners 
is  at  present  unattainable,  simply  because  the  immediately 
prospective  price  of  coal  would  not  coyer  the  cost  of  such 
deep  sinking  and  working;  but  as  prices  go  up,  pits  will 
go  down,  deeper  and  deeper  still. 

The  obstacles  which  are  assumed  to  determine  the  4000 
feet  limit  are  increasing  density  due  to  greater  pressure, 
and  the  elevation  of  temperature  which  proceeds  as  we  go 
downwards.  The  first  of  these  difficulties  has,  I  suspect, 
been  very  much  overstated,  if  not  altogether  misunder- 
stood; though  it  is  but  fair  to  add  that  Mr.  Hull,  who 
most  prominently  dwells  upon  it,  does  so  with  all  just  and 
philosophic  caution.  He  says  that  "it  is  impossible  to 
speak  with  certainty  of  the  effect  of  the  accumulative  weight 
of  3000  or  4000  feet  of  strata  on  mining  operations.  In 
all  probability  one  effect  would  be  to  increase  the  density 
of  the  coal  itself,  and  of  its  accompanying  strata,  so  as  to 
increase  the  difficulty  of  excavating,"  and  he  concludes  by 
stating  that  "in  the  face  of  these  two  obstacles— tempera- 
ture and  pressure,  ever  increasing  with  the  depth — I  have 
considered  it  Utopian  to  include  in  calculations  having  ref- 
erence to  coal  supply  any  quantity,  however  considerable, 
which  lies  at  a  greater  depth  than  4000  feet.  Beyond  that 
depth  I  do  not  believe  that  it  will  be  found  practicable  to 
penetrate.  Nature  rises  up,  and  presents  insurmountable 
barriers."* 

On  one  point  I  differ  entirely  from  Mr.  Hull,  viz.,  the 
conclusion  that  the  increased  "density  of  the  coal  itself  and 
of  its  accompanying  strata"  will  offer  any  serious  obstacle. 
On  the  contrary,  there  is  good  reason  to  believe  that  such 
density  is  one  of  the  essential  conditions  for  working  deep 
coal.  Even  at  present  depths  of  working,  density  and 
hardness  of  the  accompanying  strata  is  one  of  the  most  im- 
portant aids  to  easy  and  cheap  coal-getting.  "With  a  dense 
roof  and  floor  the  collier  works  vigorously  and  fearlessly, 
and  he  escapes  the  serious  cost  of  timbering. 


hThe  Coal  Fields  of  Great  Britain,"  pp.  447,  448. 


THE  LIMITS  OF  OUR  COAL  SUPPLY.  197 

Those  who  have  never  been  underground,  and  only  read 
of  colliery  disasters,  commonly  regard  the  fire-damp  and 
choke-damp  as  the  collier's  most  deadly  enemies,  but  the 
collier  himself  has  quite  as  much  dread  of  a  rotten  roof  as 
of  either  of  these:  he  knows  by  sad  experience  how  much 
bruising,  and  maiming,  and  crushing  of  human  limbs  are 
due  to  the  friability  of  the  rock  above  his  head.  Mr.  Hull 
quotes  the  case  of  the  Dunkinfield  colliery,  where,  at  a 
depth  of  about  2500  feet,  the  pressure  is  "so  resistless  as 
to  crush  in  circular  arches  of  brick  four  feet  thick,"  and  to 
snap  a  cast-iron  pillar  in  twain;  but  he  does  not  give  any 
account  of  the  density  of  the  accompanying  strata  at  the 
place  of  these  occurrences.  I  suspect  that  it  was  simply  a 
want  of  density  that  allowed  the  superincumbent  pressure 
to  do  such  mischief.  The  circular  arches  of  brick  four 
feet  thick  were  but  poor  substitutes  for  a  roof  of  solid  rock 
of  40  or  400  feet  in  thickness;  an  arch  cut  in  such  a  rock 
would  be  all  key-stone:  and  I  may  safely  venture  to  affirm 
that  if,  in  the  deep  sinkings  of  the  future,  we  do  encounter 
the  increased  density  which  Mr.  Hull  anticipates,  this  will 
be  altogether  advantageous.  I  fear,  however,  that  it  will 
not  be  so,  that  the  chief  difficulty  of  deep  coal-mining  will 
arise  from  occasional  "  running  in"  due  to  deficient  den- 
sity, and  that  this  difficulty  will  occur  in  about  the  same 
proportion  of  cases  as  at  present,  but  will  operate  more 
seriously  at  the  greater  depths. 

A  very  interesting  subject  for  investigation  is  hereby 
suggested.  Do  rocks  of  given  composition  and  formation 
increase  in  density  as  they  dip  downwards;  and  if  so,  does 
this  increase  of  density  follow  any  law  by  which  we  may 
.  determine  whether  their  power  of  resisting  superincumbent 
pressure  increases  in  any  approach  to  the  ratio  of  the  in- 
creasing pressure  to  which  they  are  naturally  subjected? 
If  the  increasing  density  and  power  of  resistance  reaches 
or  exceeds  this  ratio,  deep  mining  has  nothing  to  fear  from 
pressure.  If  they  fall  short  of  it,  the  difficulties  arising 
from  pressure  may  be  serious.  Friability,  viscosity,  and 
power  of  resisting  a  crushing  strain  must  be  considered  jn 
reference  to  this  question. 

Mr.  Hull  has  collected  a  considerable  amount  of  data 


198  SCIENCE  IN  SHORT  CHAPTERS. 

bearing  upon  the  rate  of  increase  of  temperature  with 
depth.  His  conclusions  give  a  greater  rate  of  increase 
than  is  generally  stated  by  geologists;  but  for  the  present 
argument  I  will  accept,  without  prejudice,  as  the  lawyers 
say,  his  basis  of  a  range  of  1°  F.  for  60  feet.  According 
to  this,  the  rocks  will  reach  99. 6°,  a  little  above  blood-heat, 
at  3000  feet,  and  116.3°  at  the  supposed  limit  of  4000  feet. 
It  is  assumed  by  Mr.  Hull,  by  the  Commissioners,  and 
most  other  authorities,  that  this  rock  temperature  of  116° 
will  limit  the  possibilities  of  coal-mining.  At  the  average 
prices  of  the  last  three  years,  or  the  prospective  prices  of 
the  next  three  years,  this  temperature  may  be,  like  difficul- 
ties of  the  thin  seams,  an  insurmountable  barrier;  but  I 
contend  that  at  higher  prices  we  may  work  coal  at  this, 
and  even  far  higher,  rock  temperatures ;  that  it  matters 
not  how  high  the  thermometer  rises  as  we  descend,  we 
shall  still  go  lower  and  still  get  coal  so  long  as  prices  rise 
with  the  mercury.  Given  this  condition,  and  I  have  no 
doubt  that  coal  may  be  worked  where  the  rock  temperature 
shall  reach  or  even  exceed  212°.  I  do  not  say  that  we 
shall  actually  work  coal  at  such  depths;  but  if  we  do  not, 
the  reason  will  be,  not  that  the  thermometer  is  too  high, 
but  that  prices  are  too  low;  in  other  words,  value,  not 
temperature,  will  determine  the  working  limits. 

Mr.  Leifchild,  in  the  last  number  of  the  "  Edinburgh 
Review,"  in  discussing  this  question,  tells  us  that  "the 
normal  heat  of  our  blood  is  98°,  and  fever  heat  commences 
at  100°,  and  the  extreme  limit  of  fever  heat  may  be  taken 
at  112°.  Dr.  Thudichum,  a  physician  who  has  specially 
investigated  this  subject,  has  concluded  from  experiments 
on  his  own  body  at  high  temperatures,  that  at  a  heat  of 
1400  no  work  whatever  could  be  carried  on,  and  that  at  a 
temperature  of  from  130°  to  140°  only  a  very  small  amount 
of  labor,  and  that  at  short  periods,  was  practicable;  and 
further,  that  human  labor  daily,  and  at  ordinary  periods, 
is  limited  by  100°  of  temperature,  as  a  fixed  point,  and 
then  the  air  must  be  dry,  for  in  moist  air  he  did  not  think 
men  could  endure  ordinary  labor  at  a  temperature  exceed- 
ing 90°." 

It  may  be  presumptuous  on  my  part  to  dispute  the  con- 


THE  LIMITS  OF  OUR   COAL  SUPPLY.  199 

elusions  of  a  physician  on  such  a  subject,  but  I  do  so 
nevertheless,  as  the  data  required  are  simple  practical  facts 
such  as  are  better  obtained  by  furnace-working  than  by 
sick-room  experience. 

During  the  hottest  days  of  the  summer  of  1868  I  was 
engaged  in  making  some  experiments  in  the  re-heating 
furnaces  at  Sir  John  Brown  &  Co. 's  works,  Sheffield,  and 
carried  a  thermometer  about  with  me  which  I  suspended 
in  various  places  where  the  men  were  working.  At  the 
place  where  I  was  chiefly  engaged  (a  corner  between  two 
sets  of  furnaces),  the  thermometer,  suspended  in  a  position 
where  it  was  not  affected  by  direct  radiations  from  the 
open  furnaces,  stood  at  120°  while  the  furnace  doors  were 
shut.  The  radiant  heat  to  which  the  men  themselves  were 
exposed  while  making  their  greatest  efforts  in  placing  and 
removing  the  piles  was  far  higher  than  this,  but  I  cannot 
state  it,  not  having  placed  the  thermometer  in  the  position 
of  the  men.  In  one  of  the  Bessemer  pits  the  thermometer 
reached  140°,  and  men  worked  there  at  a  kind  of  labor 
demanding  great  muscular  effort.  It  is  true  that  during 
this  same  week  the  puddlers  were  compelled  to  leave  their 
work;  but  the  tremendous  amount  of  concentrated  exer- 
tion demanded  of  the  puddler  in  front  of  a  furnace,  which, 
during  the  time  of  removing  the  balls,  radiates  a  degree  of 
heat  quite  sufficient  to  roast  a  sirloin  of  beef  if  placed  in 
the  position  of  the  pudd^s  hands,  is  beyond  comparison 
with  that  which  would  be  demanded  of  a  collier  working 
even  at  a  depth  giving  a  theoretical  rock  temperature  of 
212°,  and  aided  by  the  coal-cutting  and  other  machinery 
that  sufficiently  high  prices  would  readily  command.  In 
some  of  the  operations  of  glass-making,  the  ordinary  sum- 
mer working  temperature  is  considerably  above  100°,  and 
the  radiant  heat  to  which  the  workmen  are  subjected  far 
exceeds  212°.  This  is  the  case  during  a  "pot  setting," 
and  in  the  ordinary  work  of  flashing  crown  glass. 

As  regards  the  mere  endurance  of  a  high  temperature, 
the  well-known  experiments  of  Blagden,  Sir  Joseph  Banks, 
and  others  have  shown  that  the  human  body  can  endure 
for  short  periods  a  temperature  of  260°  F.,  and  upwards. 
My  own  experience  of  furnace-work,  and  of  Turkish  baths, 


200  SCIENCE  IN  SHORT  CHAPTERS. 

quite  satisfies  me  that  I  could  do  a  fair  day's  work  of  six  or 
eight  hours  in  a  temperature  of  130°  F.,  provided  I  were 
free  from  the  encumbrances  of  clothing,  and  had  access  to 
abundance  of  tepid  water.  This  in  a  still  atmosphere:  but 
with  a  moving  current  of  dry  air  capable  of  promoting 
vigorous  evaporation  from  the  skin,  I  suspect  that  the 
temperature  might  be  ten  or  fifteen  degrees  higher.  I 
enjoy  ordinary  walking  exercise  in  a  well-ventilated  Turkish 
bath  at  150°,  and  can  endure  it  at  180°. 

In  order  to  obtain  further  information  on  this  point,  I 
have  written  to  Mr.  Tyndall,  the  proprietor  of  the  Turkish 
baths  at  Newington  Butts.  He  is  an  architect,  who  has 
had  considerable  experience  in  the  employment  of  workmen 
and  in  the  construction  of  Turkish  baths  and  other  hot-air 
chambers.  He  says:  "  Shampooers  work  in  my  establish- 
ment from  four  to  five  hours  at  a  time  in  a  moist  atmos- 
phere at  a  temperature  ranging  from  105°  to  110°.  I  have 
myself  worked  twenty  hours  out  of  twenty-four  in  one  day 
in  a  temperature  over  110°.  Once  for  one  half-hour  I 
shampooed  in  185°.  At  the  enamel  works  in  Pimlico, 
belonging  to  Mr.  Mackenzie,  men  work  daily  in  a  heat  of 
over  300°.  The  moment  a  man  working  in  a  110°  heat 
begins  to  drink  alcohol,  his  tongue  gets  parched,  and  he  is 
obliged  to  continue  drinking  while  at  work,  and  the  brain 
gets  so  excited  that  he  cannot  do  half  the  amount.  I 
painted  my  skylights,  taking  me  about  four  hours,  at  a 
temperature  of  about  145°;  also  tne  hottest  room  skylights, 
which  took  me  one  hour,  coming  out  at  intervals  for  "  a 
cooler,"  at  a  temperature  of  180°.  I  may  add  in  con- 
clusion, that  a  man  can  work  well  in  a  moist  temperature  of 
110°  if  he  perspires  freely." 

The  following,  by  a  writer  whose  testimony  may  be 
safely  accepted,  is  extracted  from  an  account  of  ordinary 
passenger  ships  of  the  Red  Sea,  in  the  "Illustrated  News,'" 
of  November  9,  1872:  "  The  temperature  in  the  stoke-hole 
was  145°.  The  floor  of  this  warm  region  is  close  to  the 
ship's  keel,  so  it  is  very  far  below.  There  are  twelve 
boilers,  six  on  each  side,  each  with  a  blazing  furnace, 
which  has  to  be  opened  at  regular  intervals  to  put  in  new 
coals,  or  to  be  poked  up  Avith  long  iron  rods.  This  is  the 


THE  LIMITS  OF  OUR  COAL  SUPPLY.  201 

duty  of  the  poor  wretches  who  are  doomed  to  this  work. 
It  is  hard  to  believe  that  human  beings  could  be  got  to 
labor  under  such  conditions,  yet  such  persons  are  to  be 
found.  The  work  of  stoking  or  feeding  the  fires  is  usually 
done  by  Arabs,  while  the  work  of  bringing  the  coal  from 
the  bunkers  is  done  by  sidi-wallahs  or  negroes.  At  times 
some  of  the  more  intelligent  of  these  are  promoted  to  the 
stoking.  The  negroes  who  do  this  kind  of  work  come 
from  Zanzibar.  They  are  generally  short  men,  with  strong 
limbs,  round  bullet  heads,  and  the  very  best  of  good  nature 
in  their  dispositions.  Some  of  them  will  work  half  an 
hour  in  such  a  place  as  the  stoke-hole  without  a  drop  of 
perspiration  on  their  dark  skins.  Others,  particularly  the 
Arabs,  when  it  is  so  hot  as  it  often  is  in  the  Eed  Sea,  have 
to  be  carried  up  in  a  fainting  condition,  and  are  restored 
to  animation  by  dashing  buckets  of  water  over  them  as 
they  lie  on  deck." 

It  must  be  remembered  that  the  theoretical  temperature 
of  116°  at  4000  feet,  the  133°  at  5000  feet,  or  the  150°  at 
6000  feet,  are  the  temperatures  of  the  undisturbed  rock ; 
that  this  rock  is  a  bad  conductor  of  heat,  whose  surface  may 
be  considerably  cooled  by  radiation  and  convection;  and 
therefore  we  are  by  no  means  to  regard  the  rock  tempera- 
ture as  that  of  the  air  of  the  roads  and  workings  of  the 
deep  coal-pits  of  the  future.*  It  is  true  that  the  Eoyal 
Commissioners  have  collected  many  facts  showing  that  the 
actual  difference  between  the  face  of  the  rocks  of  certain 
pits  and  the  air  passing  through  them  is  but  small;  but 
these  data  are  not  directly  applicable  to  the  question  under 
consideration  for  the  three  following  reasons: 

First.  The  comparisons  are  made  between  the  tempera- 
ture of  the  air  and  the  actual  temperature  of  the  opened 

*In  a  paper  on  the  Comstock  mines,  read  at  the  Pittsburg  meet- 
ing of  the  American  Institute  of  Mining  Engineers  in  1879,  by  Mr. 
John  A.  Church,  tiie  hot  mine  waters  are  described  as  reaching  158° 
Fahr.  (so  hot  that  men  have  been  scalded  to  death  by  falling  into 
them).  Tlie  highest  recorded  air  temperature  there  is  128°.  «  These 
are  silver  mines,  and  vigorously  worked  in  spite  of  this  tempera- 
ture and  great  humidity.  A  much  higher  temperature  is  endurable 
in  dry  air. 


202  801ENOE  IN  SHORT  CHAPTERS. 

and -'already  cooled  strata,  while  the  question  to  be  solved 
is  the  difference  between  the  theoretical  temperature  of  the 
unopened  earth  depths  and  that  of  the  air  in  roads  and 
workings  to  be  opened  through  them. 

Second.  The  cooling  effect  of  ventilation  must  (as  the 
Commissioners  themselves  state)  increase  in  a  ratio  which 
"  somewhat  exceeds  the  ratio  of  the  difference  between  the 
temperature  of  the  air  and  that  of  the  surrounding  surface 
with  which  it  is  in  contact."  Thus,  the  lower  we  proceed 
the  more  and  more  effectively  cooling  must  a  given  amount 
of  ventilation  become. 

The  third,  and  by  far  the  most  important,  reason  is,  that 
in  the  deep  mining  of  the  future,  special  means  will  be 
devised  and  applied  to  the  purpose  of  lowering  the  temper- 
ature of  the  workings;  that  as  the  descending  efforts  of  the 
collier  increase  with  the  ascending  value  of  the  coal,  a  new 
problem  will  be  offered  for  solution,  and  the  method  of 
Avorking  coal  will  be  altered  accordingly.  In  the  cases 
quoted  by  the  Commissioners,  the  few  degrees  of  cooling 
were  effected  by  a  sytem  of  ventilation  that  was  devised  to 
meet  the  requirements  of  respiration,  and  not  for  the  pur- 
pose of  cooling  the  mine. 

It  would  be  very  presumptuous  for  anyone  in  1873  to 
say  how  this  special  cooling  will  actually  be  effected,  but  I 
will  nevertheless  venture  to  indicate  one  or  two  principles 
which  may  be  applied  to  the  solution  of  the  problem.  First 
of  all,  it  must  be  noted  that  very  deep  mines  are  usually 
dry;  and  there  is  good  reason  to  believe  that,  before  reach- 
ing the  Commissioners'  limit  of  4000  feet,  dry  mining  would 
be  the  common,  and  at  and  below  4000  feet  the  universal, 
case.  At  present  we  usually  obtain  coal  from  water-bearing 
strata,  and  all  our  arrangements  are  governed  by  this  very 
serious  contingency.  With  water  removed,  the  whole  sys- 
tem of  coal-mining  may  be  revolutionized,  and  thus  the 
aspect  of  this  problem  of  cooling  the  workings  would  be- 
come totally  changed. 

Those  who  are  acquainted  with  the  present  practice  of 
mining  are  aware  that  when  an  estate  is  taken,  and  about 
to  be  worked  for  coal,  the  first  question  to  be  decided  is  the 
dip  of  the  measures,  in  order  that  the  sinking  may  be  made 


THE  LIMITS  OF  OUR   COAL  SUPPLY.  SOS 

"on  the  deep"  of  the  whole  range.  The  pits  are  not  sunk 
at  that  part  of  the  same  range  where,  at  first  sight,  the  coal 
appears  the  most  accessible,  but,  on  the  contrary,  at  the 
deepest  part.  It  is  then  carried  on  to  some  depth  below 
the  coal  seam  which  is  to  be  worked,  in  order  to  form  a 
"  sumpf  "  or  receptacle  from  which  the  water  may  be  wound 
or  pumped.  The  necessity  for  this  in  water-bearing  strata 
is  obvious  enough.  If  the  collier  began  at  the  shallowest 
portion  of  his  range,  and  attempted  to  proceed  downwards, 
he  would  be  "drowned  out"  unless  he  worked  as  a  coal- 
diver  rather  than  a  coal-miner.  By  sinking  in  the  deep  he 
works  upwards,  away  from  the  water,  which  all  drains  down 
to  the  sumpf,  from  which  it  is  pumped. 

The  modern  practice  is  to  sink  "  a  pair  of  pits,"  both  on 
the  deep,,  and  within  a  short  distance  of  each  other.  The 
object  of  the  second  is  ventilation.  By  contrivances,  which 
I  need  not  here  detail,  the  air  is  made  to  descend  one  of  the 
pits,  "the  downcast  shaft,"  then  to  traverse  the  roads  and 
workings  wherein  ventilation  is  required,  and  return  by  a 
reverse  route  to  the  "upcast  shaft,"  by  which,  it  ascends  to 
the  surface. 

Thus  it  will  be  seen  that,  whenever  the  temperature  of 
the  roads  and  workings  exceeds  that  of  the  outer  atmos- 
phere; the  air  currents  have  to  be  forced  to  travel  through 
the  mine  in  a  direction  contrary  to  their  natural  course. 
The  cooler  air  of  the  downcast  shaft  has  to  climb"  the  in- 
clined roads,  and  then  after  attaining  its  maximum  temper- 
ature in  the  fresh  workings  must  descend  the  roads  till  it 
reaches  the  upcast  shaft.  The  cool  air  must  rise  and  the 
warmer  air  descend. 

What,  then,  would  be  the  course  of  the  mining  engineer 
when  all  the  existing  difficulties  presented  by  water-bearing 
strata  should  be  removed,  and  their  place  taken  by  a  new 
and  totally  different  obstacle,  viz.,  high  temperature? 
Obviously  to  reverse  the  present  mode  of  working — to  sink 
on  the  upper  part  of  the  range  and  drive  downwards.  In 
such  a  system  of  working  the  ventilation  of  the  pit  will  be 
most  powerfully  aided  or  altogether  effected  by  natural 
atmospheric  currents.  An  upcast  once  determined  by 
artificial  means,  it  will  thereafter  proceed  spon  taueousl}r, 


204  SCIENCE  IN  SHORT  CHAPTERS. 

as  the  cold  air  of  the  downcast  shaft  will  travel  by  a  de- 
scending road  to  the  workings,  and  then  after  becoming 
heated  will  simply  obey  the  superior  pressure  of  the  heavy 
column  behind,  and  proceed  by  an  upward  road  to  the  up- 
cast shaft.  As  the  impelling  force  of  the  air  current  will 
be  the  difference  between  the  weight  of  the  cool  column  of 
air  in  the  downcast  shaft  and  roads  and  the  warm  column 
in  the  upcast,  the  available  force  of  natural  ventilation  and 
cooling  will  increase  just  as  demanded,  i.e.,  it  will  increase 
with  the  depth  of  the  workings  and  the  heat  of  the  rocks. 
A  mining  engineer  who  knows  what  is  actually  done  with 
present  arrangements,  will  see  at  once  that  with  the  above- 
stated  advantages  a  gale  of  wind  or  even  a  hurricane  might 
be  directed  through  any  particular  roads  or  long- wall  work- 
ings that  were  once  opened.  Let  us  suppose  the  depth  to 
be  5000  feet,  the  rock  temperature  at  starting  133°,  and 
that  of  the  outer  air  60°,  we  should  have  a  torrent  of  air,  73° 
cooler  than  the  rocks,  rushing  furiously  downwards,  then 
past  the  face  of  the  heated  strata,  and  absorbing  its  heat 
to  such  an  exent  that  the  upcast  shaft  would  pour  forth 
a  perpetual  blast  of  hot  air  like  a  gigantic  furnace  chim- 
ney. 

But  this  is  not  all;  the  heat  and  dryness  of  these  deep 
workings  of  the  future  place  at  our  disposal  another  and 
still  more  efficient  cooling  agency  than  even  that  of  a 
hurricane  of  dry-air  ventilation.  In  the  first  part  of  the 
sinking  of  the  deep  shafts  the  usual  water-bearing  strata 
would  be  encountered,  and  the  ordinary  means  of  "tub- 
bing" or  "coffering"  would  probably  be  adopted  for  tem- 
porary convenience  during  sinking.  Doorways,  however, 
would  be  left  in  the  tubbing  at  suitable  places  for  tapping 
at  pleasure  the  wettest  and  most  porous  of  the  strata. 
Streams  of  cold  water  could  thus  be  poured  down  the  sides 
of  the  shaft,  which,  on  reaching  the  bottom,  Avould  flow 
by  a  downhill  road  into  the  workings.  The  stream  of  air 
Sashing  by  the  same  route  and  becoming  heated  in  its  course 
would  powerfully  assist  the  evaporation  of  the  water.  The 
deeper  and  hotter  the  pit,  the  more  powerful  would  be  these 
cooling  agencies. 

As  the  specific  heat  of  water  is  about  five  times  that  of 


THE  LIMITS  OF  OUR  COAL  SUPPLY.  205 

the  coal-measure  rocks,  or  the  coal  itself,  every  degree  of 
heat  communicated  to  each  pound  of  water  would  abstract 
one  degree  from  five  pounds  of  rocks.  But  in  the  conver- 
sion of  water  at  60°  into  vapor  at  say  100°,  the  amount  of 
heat  absorbed  is  equivalent  to  that  required  to  raise  the 
same  weight  of  water  about  1000°,  and  thus  the  effective 
cooling  power  on  the  rock  would  be  equivalent  to  5000°. 

The  workings  once  opened  (I  assume  as  a  matter  of 
course  that  by  this  time  pillar-and- stall  working  will  be 
enterely  abandoned  for  long-wall  or  something  better),  there 
would  be  no  difficulty  in  thus  pouring  streams  of  water  and 
torrents  of  air  through  the  workings  during  the  night,  prat 
any  suitable  time  preparatory  to  the  operations  of  the  miner, 
who  long  before  the  era  of  such  deep  workings  will  be 
merely  the  director  of  coal-cutting  and  loading  machinery. 

Given  a  sufficiently  high  price  for  coal  at  the  pit's  mouth 
to  pay  wages  and  supply  the  necessary  fixed  capital,  I  see 
no  insuperable  difficulty,  so  far  as  mere  temperature  is  con- 
cerned, in  working  coal  at  double  the  depth  of  the  Royal 
Commissioners'  limit  of  possibility.  At  such  a  depth  of 
8000  feet  the  theoretical  rock-temperature  is  183°. 

By  the  means  above  indicated,  I  have  no  doubt  that  this 
could  be  reduced  to  an  air  temperature  below  110° — that 
at  which  Mr.  Tyndall's  shampooers  ordinarily  work.  Of 
course  the  newly-exposed  face  of  the  coal  would  have  its 
initial  temperature  of  183°;  but  this  is  a  trivial  heat  com- 
pared to  the  red-hot  radiant  surfaces  to  which  puddlers, 
shinglers,  glassmakers,  etc.,  are  commonly  exposed. 
Divested  of  the  incumbrance  of  clothing,  with  the  whole 
surface  of  the  skin  continuously  fanned  by  a  powerful  stream 
of  air — which,  during  working  hours  need  be  but  partly 
saturated  with  vapor — a  sturdy  midland  or  north-country- 
man would  work  merrily  enough  at  short  hours  and  high 
wages,  even  though  the  newly-exposed  face  of  coal  reached 
212°;  for  we  must  remember  that  this  new  coal-face  would 
only  correspond  to  the  incomparably  hotter  furnace-doors 
and  fires  of  the  steamship  stoke-holes. 

The  high  temperature  at  8000  or  even  10,000  feet  would 
present  a  really  serious  difficulty  during  the  first  opening  of 
communications  between  the  two  pits.  A  spurt  of  brave 


206  SCIENCE  IN  SHORT  CHAPTERS. 

effort  would  here  be  necessary,  and  if  anybody  doubts 
whether  Englishmen  could  be  found  to  make  the  effort,  let 
him  witness  a  "  pot-setting"  at  a  glass-house.  Negro  labor 
might  be  obtained  if  required,  but  my  experience  among 
English  workmen  leads  me  to  believe  that  they  will  never 
allow  negroes  or  any  others  to  beat  them  at  home  in  any 
kind  of  work  where  the  wages  paid  are  proportionate  to  the 
effort  demanded. 

If  I  am  right  in  the  above  estimates  of  working  possi- 
bilities, our  coal  resources  may  be  increased  by  about  forty 
thousand  millions  of  tons  beyond  the  estimate  of  the  Com- 
missioners. To  obtain  such  an  additional  quantity  will 
certainly  be  worth  an  effort,  and  unless  we  suffer  a  far  worse 
calamity  than  the  loss  of  all  our  minerals,  viz.,  a  deteriora- 
tion of  British  energy,  the  effort  will  assuredly  be  made. 

I  have  said  repeatedly  that  it  is  not  physical  difficulties 
but  market  value  that  will  determine  the  limits  of  our  coal- 
mining. This,  like  all  other  values,  is  of  course  determined 
by  the  relation  between  demand  and  supply.  Fuel  being 
one  of  the  absolute  necessaries  of  life,  the  demand  for  it 
must  continue  so  long  as  the  conditions  of  human  existence 
remain  as  at  present,  and  the  outer  limits  of  the  possible 
value  of  coal  will  be  determined  by  that  of  the  next  cheapest 
kind  of  fuel  which  is  capable  of  superseding  it. 

We  begin  by  working  the  best  and  most  accessible 
seams,  and  whije  those  remain  in  abundance  the  average 
value  of  coal  will  be  determined  by  the  cost  of  producing  it 
under  these  easy  conditions.  Directly  these  most  accessible 
seams  cease  to  supply  the  whole  demand,  the  market  value 
rises  until  it  becomes  sufficient  to  cover  the  cost  of  work- 
ing the  less  accessible;  and  the  average  value  will  be 
regulated  not  by  the  cost  of  working  what  remains  of  the 
first  or  easy  mines,  but  by  that  of  working  the  most  difficult 
that  must  be  worked  in  order  to  meet  the  demand.  This  is 
a  simple  case  falling  under  the  well-established  economic 
law,  that  the  natural  or  cost  value  of  any  commodity  is 
determined  by  the  cost  value  of  the  most  costly  portion  of 
it.  Thus,  the  only  condition  under  which  we  can  proceed 
to  sink  deeper  and"  deeper,  is  a  demand  of  sufficient  energy 
to  keep  pace  with  the  continually  increasing  cost  of  pro'- 


THE  LIMITS  OF  OUR   COAL  SUPPLY.  20? 

duction.  This  condition  can  only  be  fulfilled  when  there  is 
no  competing  source  of  cheaper  production  which  is  ade- 
quate to  supply  the  demand. 

The  question  then  resolves  inself  into  this:  Is  any  source 
of  supply  likely  to  intervene  that  will  prevent  the  value  of 
coal  from  rising  sufficiently  to  cover  the  cost  of  working 
the  coal  seams  of  4000  feet  and  greater  depth?  Without 
entering  upon  the  question  of  peat  and  wood  fuel,  both  of 
which  will  for  some  uses  undoubtedly  come  into  competition 
with  British  coal  as  it  rises  in  value,  I  believe  that  there  are 
sound  reasons  for  concluding  that  our  London  fireplaces, 
and  those  of  other  towns  situated  on  the  sea-coast  and  the 
banks  of  navigable  rivers,  will  be  supplied  with  transatlantic 
coal  long  before  we  reach  the  Commissioner's  limit  of  4000 
feet.  The  higest  prices  of  last  winter,  if  steadily  main- 
tained, would  be  sufficient  to  bring  about  this  important 
change.  Temporary  upward  jerks  of  the  price  of  coal  have 
very  little  immediate  effect  upon  supply,  as  the  surveying, 
conveyance,  boring,  sinking,  and  fully  opening  of  a  new 
coal  estate  is  a  work  of  some  years. 

The  Eoyal  Commissioners"  estimate  that  the  North- 
American  coal-fields  contain  an  untouched  coal  area  equal 
to  seventy  times  the  whole  of  ours.  Further  investigation 
is  likely  to  increase  rather  than  diminish  this  estimate.  An 
important  portion  of  this  vast  source  of  supply  is  well 
situated  for  shipment,  and  may  be  easily  worked  at  little 
cost.  Hitherto,  the  American  coal-fields  have  been  greatly 
neglected,  partly  on  account  of  the  temptations  to  agri- 
cultural occupation  which  are  afforded  by  the  vast  area  of  the 
American  continent,  and  partly  by  the  barbarous  barriers  of 
American  politics.  Large  amounts  of  capital  which,  under 
the  social  operation  of  the  laws  of  natural  selection,  would 
have  been  devoted  to  the  unfolding  of  the  vast  mineral 
resources  of  the  United  States,  are  still  wastefully  invested 
in  the  maintenance  of  protectively  nursed  and  sickly 
imitation  of  English  manufactures.  When  the  political 
civilization  of  the  United  States  become  sufficiently 
advanced  to  establish  a  national  free-trade  policy,  this  per- 
verted capital  will  flow  into  its  natural  channels,  and  the 
citizens  of  the  States  will  be  supplied  with  the  more  highly 


208  SCIENCE  IN  SHORT  CHAPTERS. 

elaborated  industrial  products  at  a  cheaper  rate  than  at 
present,  by  obtaining  them  in  exchange  for  their  super- 
abundant raw  material  from  'those  European  countries 
where  population  is  overflowing  the  raw  material  supplies. 

When  this  time  arrives,  and  it  may  come  with  the  cha- 
racteristic suddenness  of  American  changes,  the  question  of 
American  versus  English  coal  in  the  English  markets  will 
reduce  itself  to  one  of  horizontal  versus  vertical  difficulties. 
If  at  some  future  period  the  average  depth  of  the  Newcastle 
coal-pits  becomes  3000  feet  greater  than  those  of  the  pits 
near  the  coast  of  the  Atlantic  or  American  lakes,  and  if  the 
horizontal  difficulties  of  3000  miles  of  distance  are  less 
than  the  vertical  difficulties  of  3000  feet  of  depth,  then 
coals  will  be  carried  from  America  to  Newcastle.  They 
will  reach  London  and  the  towns  on  the  South  Coast 
before  this,  that  is,  when  the  vertical  difficulties  at  New- 
castle plus  those  of  horizontal  traction  from  Newcastle  to 
the  south,  exceed  those  of  eastward  traction  across  the 
Atlantic. 

As  the  cost  of  carriage  increases  in  a  far  smaller  ratio 
than  the  open  ocean  distance,  there  is  good  reason  for  con- 
cluding that  the  day  when  London  houses  will  be  warmed 
by  American  coal  is  not  very  far  distant.  We,  in  England, 
who  have  outgrown  the  pernicious  folly  of  "protecting 
native  industry,'  will  heartily  welcome  so  desirable  a  con- 
summation. It  will  render  unnecessary  any  further  inquiry 
into  the  existence  of  London  "coal  rings"  or  combinations 
for  restricted  output  among  colliers  or  their  employers.  If 
any  morbid  impediments  to  the  free  action  of  the  coal  trade 
do  exist,  the  stimulating  and  purgative  influence  of  foreign 
competition  will  rapidly  restore  the  trade  to  a  healthy 
condition. 

The  effect  of  such  introduction  of  American  coal  will 
not  be  to  perpetually  lock  up  our  deep  coal  nor  even  to  stop 
our  gradual  progress  towards  it.  We  shall  merely  proceed 
downwards  at  a  much  slower  rate,  for  in  America,  as  with 
ourselves,  the  easily  accessible  coal  will  be  first  worked, 
and  as  that  becomes  exhausted,  the  deeper,  more  remote, 
thinner,  and  inferior  will  only  remain  to  be  worked  at  con- 
tinually increasing  cost.  When  both  our  own  and  foreign 


THE  LIMITS  OF  OUR  COAL  SUPPLY.  209 

coal  cost  more  than  peat,  or  wood,  or  other  fuel,  then  and 
therefore  will  coal  become  quite  inaccessible  to  us,  and  this 
will  probably  be  the  case  long  before  we  are  stopped  by  the 
physical  obstacles  of  depth,  density,  or  high  temperature. 

As  this  rise  of  value  must  of  necessity  be  gradual,  and  as 
the  superseding  of  British  by  foreign  coal,  as  well  as  the 
final  disuse  of  coal,  will  gradually  converge  from  the  cir- 
cumference towards  the  centres  of  supply,  from  places  dis- 
tant from  coal-pits  to  those  close  around  them,  we  shall 
have  ample  warning  and  opportunity  for  preparing  for  the 
social  changes  that  the  loss  of  the  raw  material  will  enforce. 

The  above-quoted  writer,  in  the  "Edinburgh  Review," 
expresses  in  strong  and  unqualified  terms  an  idea  that  is 
very  prevalent  in  England  and  abroad:  he  says  that,  "The 
course  of  manufacturing  supremacy  of  wealth  and  of  power 
is  directed  by  coal.  That  wonderful  mineral,  of  the  pos- 
session of  which  Englishmen  have  thought  so  little  but 
wasted  so  much,  is  the  modern  realization  of  the  philoso- 
pher's stone.  This  chemical  result  of  primeval  vegetation 
has  been  the  means  by  its  abundance  of  raising  this  coun- 
try to  an  unprecedented  height  of  prosperity,  and  its  de- 
ficiency might  have  the  effect  of  lowering  it  to  slow  de- 
cline." 

*  *  "  It  raises  up  one  people  and  casts  down  another; 
it  makes  railways  on  land  and  paths  on  the  sea.  It  founds 
cities,  it  rules  nations,  it  changes  the  course  of  empires." 

The  fallacy  of  these  customary  attributions  of  social  po- 
tency to  mere  mineral  matter  is  amply  shown  by  facts  that 
are  previously  stated  by  the  reviewer  himself.  He  tells  us 
that  "the  coal-fields  of  China  extend  over  an  area  of  400,- 
000  square  miles;  and  a  good  geologist,  Baron  Von  Richt- 
hofen,  has  reported  that  he  himself  has  found  a  coal-field 
in  the  province  of  Hunau  covering  an  area  of  21,700  square 
miles,  which  is  nearly  double  our  British  coal  area  of  12,000 
square  miles.  In  the  province  of  Shansi,  the  Baron  dis- 
covered nearly  30,000  square  miles  of  coal  with  unrivaled 
facilities  for  mining.  But  all  these  vast  coal-fields,  capable 
of  supplying  the  whole  world  for  some  thousands  of  years 
to  come,  are  lying  un worked." 

If  "the  course  of  manufacturing  supremacy  of  wealth 


210  SCIENCE  IN  SHORT  CHAPTERS. 

and  of  power"  were  directed  by  coal,  then  China,  which 
possesses  33  '3  times  more  of  this  directive  force  than  Great 
Britain,  and  had  so  early  a  start  in  life,  should  be  the  su- 
preme summit  of  the  industrial  world.  If  this  solid  hydro- 
carbon "raises  up  one  people  and  casts  down  another,"  the 
Chinaman  should  be  raised  thirty-three  times  and  three 
tenths  higher  than  the  Englishman;  if  it  "  makes  railways 
on  land  and  paths  on  the  sea,"  the  Chinese  railways  should 
be  33 '3  times  longer  than  ours,  and  the  tonnage  of  their 
mercantile  marine  33  -3  times  greater. 

Every  addition  to  our  knowledge  of  the  mineral  resources 
of  other  parts  of  the  world  carries  us  nearer  and  nearer  to 
the  conclusion  that  the  old  idea  of  the  superlative  abund- 
ance of  the  natural  mineral  resources  of  England  is  a  delu- 
sion. We  are  gradually  discovering  that,  with  the  one 
exception  of  tin-stone,  we  have  but  little  if  any  more  than 
an  average  supply  of  useful  ores  and  mineral  fuel.  It  is  a 
carious  fact,  and  One  upon  which  we  may  profitably  pon- 
der, that  the  poorest  and  the  worst  iron  ores  that  have  ever 
been  commercially  reduced,  are  those  of  South  Staffordshire 
and  the  Cleveland  district,  and  these  are  the  two  greatest 
iron-making  centres  of  the  world.  There  are  no  ores  of 
copper,  zinc,  tin,  nickel,  or  silver  in  the  neighborhood  of 
Birmingham,  nor  any  golden  sands  upon  the  banks  of  the 
Rea,  yet  this  town  is  the  hardware  metropolis  of  the  world, 
the  fatherland  of  gilding  and  plating,  and  is  rapidly  be- 
coming supreme  in  the  highest  art  of  gold  and  silver  work. 

These,  and  a  multitude  of  other  analogous  facts,  abun- 
dantly refute  the  idea  that  the  native  minerals,  the  natural 
fertility,  the  navigable  rivers,  or  the  convenient  seaports, 
deterinine  the  industrial  and  commercial  supremacy  of  na- 
tions. The  moral  forces  exerted  by  the  individual  human 
molecules  are  the  true  components  which  determine  the 
resulting  force  and  direction  Of  national  progress.  It  is  the 
industry  and  skill  of  our  workmen,  the  self-denial,  the  en- 
terprise, and  organizing  ability  of  our  capitalists,  that  has 
brought  our  coal  so  precociously  to  the  surface  and  re- 
dire*cted  for  human  advantage  the  buried  energies  of  ancient 
sunbeams,  while  the  fossil  fuel  of  other  lands  has  remained 
inert. 


THE  LIMITS  OF  OUR  COAL  SUPPLY.  211 

The  foreigner  who  would  see  a  sample  of  the  source  of 
British  prosperity  must  not  seek  for  it  in  a  geological  mu- 
seum or  among  our  subterranean  rocks;  let  him  rather  stand 
on  the  Surrey  side  of  London  Bridge  from  8  to  10  A.M. 
and  contemplate  the  march  of  one  of  the  battalions  of  our 
metropolitan  industrial  army,  as  it  pours  forth  in  an  un- 
ceasing stream  from  the  railway  stations  towards  the  City. 
An  analysis  of  the  moral  forces  which  produce  the  earnest 
faces  and  rapid  steps  of  these  rank  and  file  and  officers  of 
commerce  will  reveal  the  true  elements  of  British  great- 
ness, rather  than  any  laboratory  dissection  of  our  coal  or 
ironstone. 

Fuel  and  steam-power  have  been  urgently  required  by  all 
mankind.  Englishmen  supplied  these  wants.  Their  ur- 
gency was  primary  and  they  were  first  supplied,  even  though 
the  bowels  of  the  earth  had  to  be  penetrated  in  order  to 
obtain  them.  In  the  present  exceptional  and  precocious 
degree  of  exhaustion  of  our  coal  treasures,  we  have  the 
effect  not  the  cause  of  British  industrial  success. 

If  in  a  ruder  age  our  greater  industrial  energy  enabled 
us  to  take  the  lead  in  supplying  the  ruder  demands  of  our 
fellow- creatures,  why  should  not  a  higher  culture  of  those 
same  abundant  energies  qualify  us  to  maintain  our  position 
and  enable  us  to  minister  to  the  more  refined  and  elaborate 
wants  of  a  higher  civilization?  There  are  other  necessary 
occupations  quite  as  desirable  as  coal-digging,  furnace- 
feeding,  and  cotton- spinning. 

The  approaching  exhaustion  of  our  coal  supplies  should 
therefore  serve  us  as  a  warning  for  preparation.  Britain 
will  be  forced  to  retire  from  the  coal  trade,  and  should  ac- 
cordingly prepare  her  sons  for  higher  branches  of  business, 
— for  those  in  which  scientific  knowledge  and  artistic  train- 
ing will  replace  mere  muscular  strength  and  mechanical 
skill.  "We  have  attained  our  present  material  prosperity 
mainly  by  our  excellence  in  the  use  of  steam-power;  let  us 
now  struggle  for  supremacy  in  the  practical  application  of 
brain-power. 

We  have  time  and  opportunity  for  this.  The  exhaustion 
of  our  coal  supplies  will  go  on  at  a  continually  retarding 
pace — we  shall  always  be  approaching  the  end",  but  shall 


212  SCIENCE  IN  SHORT  CHAPTERS. 

never  absolutely  reach  it,  as  every  step  of  approximation 
will  diminish  the  rate  of  approach;  like  the  everlasting 
process  of  reaching  a  given  point  by  continually  halving 
our  distance  from  it. 

First  of  all  we  shall  cease  to  export  coal ;  then  we  shall 
throw  up  the  most  voracious  of  our  coal-consuming  indus- 
tries, such  as  the  reduction  of  iron-ore  in  the  blast-furnace; 
then  copper-smelting  and  the  manufacture  of  malleable 
iron  and  steel  from  the  pig,  and  so  on  progressively.  If 
we  keep  in  view  the  natural  course  and  order  of  such  pro- 
gress, and  intelligently  prepare  for  it,  the  loss  of  our  coal 
need  not  in  the  smallest  degree  retard  the  progress  of  our 
national  prosperity. 

If,  however,  we  act  upon  the  belief  that  the  advancement 
of  a  nation  depends  upon  the  mere  accident  of  physical 
advantages,  if  we  fold  our  arms  and  wait  for  Providence  to 
supply  us  with  a  physical  substitute  for  coal,  we  shall  be- 
come Chinamen,  minus  the  unworked  coal  of  China. 

If  our  educational  efforts  are  conducted  after  the  Chinese 
model;  if  we  stultify  the  vigor  and  freshness  of  young 
brains  by  the  weary,  dull,  and  useless  cramming  of  words 
and  phrases;  if  we  poison  and  pervert  the  growing  intellect 
of  British  youth  by  feeding  it  upon  the  decayed  carcases  of 
dead  languages,  and  on  effete  and  musty  literature,  our 
progress  will  be  proportionately  Chinaward;  but  if  we  shake 
off  that  monkish  inheritance  which,  leads  so  many  of  us 
blindly  to  believe  that  the  business  of  education  is  to  pro- 
duce scholars  rather  than  men,  and  direct  our  educational 
efforts  towards  the  requirements  of  the  future  rather  than 
by  the  traditions  of  the  past,  we  need  have  no  fear  that 
Great  Britain  will  decline  with  the  exhaustion  of  her  coal- 
fields. 

The  teaching  and  training  in  schools  and  colleges  must 
be  directly  and  designedly  preparatory  to  those  of  the  work- 
shop, the  warehouse,  and  the  office;  for  if  our  progress  is 
to  be  worthy  of  our  beginning,  the  moral  and  intellectual 
dignity  of  industry  must  be  formally  acknowledged  and 
systematically  sustained  and  advanced.  Hitherto,  we  have 
been  the  first  and  the  foremost  in  utilizing  the  fossil  forces 
which  the  miner  has  unearthed;  hereafter  we  must  in  like 


"  TEE  ENGLISHMAN'S  FIRESIDE."  213 

manner  avail  ourselves  of  the  living  forces  the  philosopher 
has  revealed.  Science  must  become  as  familiar  among  all 
classes  of  Englishmen  as  their  household  fuel.  The  youth 
of  England  must  be  trained  to  observe,  generalize,  and 
investigate  the  phenomena  and  forces  of  the  world  outside 
themselves:  and  also  those  moral  forces  within  themselves, 
upon  the  right  or  wrong  government  of  which  the  success 
or  failure,  the  happiness  or  misery  of  their  lives  will  de- 
pend. 

With  such  teaching  and  training  the  future  generations 
of  England  will  make  the  best  and  most  economical  use  of 
their  coal  while  it  lasts,  and  will  etill  advance  in  material 
and  moral  prosperity  in  spite  of  its  progressive  exhaustion. 


"THE    ENGLISHMAN'S  FIKESIDE." 

DURING  the  investment  of  Paris,  the  Comptes  Rendus 
of  the  Acaclamy  of  Sciences  were  mainly  filled  with  papers 
on  the  construction  and  guidance  of  balloons;  with  the  re- 
sults of  ingenious  researches  on  methods  of  making  milk 
and  buttei^  without  the  aid  of  cows;  on  the  extraction  of 
nutritious  food  from  old  boots,  saddles,  and  other  organic 
refuse;  and  other  devices  for  rendering  the  general  famine 
more  endurable.  In  like  manner,  our  present  coal  famine 
is  directing  an  important  amount  of  scientific,  as  well  as 
commercial,  attention  to  the  subject  of  economizing  coal 
and  finding  substitutes  for  it. 

A  few  thoughtful  men  have  shocked  their  fellow- sufferers 
very  outrageously  by  wishing  that  coal  may  reach  31.  per 
ton,  and  remain  at  that  price  for  a  year  or  two.  I  confess 
that,  in  spite  of  jny  own  empty  coal-cellar  and  small  in- 
come, I  am  one  of  those  hard-hearted  cool  calculators, 
being  confident  that,  even  from  the  narrow  point  of  view 
of  my  own  outlay  in  fuel,  the  additional  amount  I  should 
thus 'pay  in  the  meantime  would  be  a  good  investment,  af- 
fording by  an  ample  return  in  the  saving  due  to  consequent 
future  cheapness. 


214  SCIENCE  IN  8HOET  CHAPTERS. 

Regarded  from  a  national  point  of  view,  I  am  convinced 
that  37.  a  ton  in  London,  and  corresponding  prices  in  other 
districts,  if  thus  maintained,  would  he  an  immense  national 
blessing.  I  say  this,  being  convinced  that  nothing  short  of 
pecuniary  pains  and  penalties  of  ruinous  severity  will  stir 
the  blind  prejudices  of  Englishmen,  and  force  them  to  de- 
sist from  their  present  stupid  and  sinful  waste  of  the  great- 
est mineral  treasure  of  the  island. 

One  of  the  grossest  of  our  national  manifestations  of 
Conservative  stupidity  is  our  senseless  idolatrous  worship 
of  that  domestic  fetish,  "the  Englishman's  fireside. "  We 
sacrifice  health,  we  sacrifice  comfort,  we  begrime  our  towns 
and  all  they  contain  with  sooty  foulness,  we.  expend  an 
amount  far  exceeding  the  interest  of  the  national  debt,  and 
discount  our  future  prospects  of  national .  prosperity,  in 
order  that  we  may  do  what?  Enjoy  the  favorite  recreation 
of  idiots.  It  is  a"  well-known  physiological  fact  that  an  ab- 
solute idiot,  with  a  cranium  measuring  sixteen  inches  in 
circumference,  will  sit  and  stare  at  a  blazing  fire  for  hours 
and  hours  continuously,  all  the  day  long,  except  when 
feeding,  and  that  this  propensity  varies  with  the  degree  of 
mental  vacuity. 

Few  sights  are  more  melancholy  than  the  contemplation 
of  a  party  of  English  fire-worshipers  seated  in  a  semicircle 
round  the  family  fetish  on  a  keen  frosty  day.  They  hud- 
dle together,  roast  their  knees,  and  grill  their  faces,  in 
order  to  escape  the  chilling  blast  that  is  brought  in  from 
all  the  chinks  of  leaky  doors  and  windows  by  the  very 
agent  they  employ,  at  so  much  cost,  for  the  purpose  of 
keeping  the  cold  away.  The  bigger  the  fire  the  greater  the 
draught,  the  hotter  their  faces  the  colder  their  backs,  the 
greater  the  consumption  of  coal  the  more  abundant  the 
crop  of  chilblains,  rheumatism,  catarrh,  and  other  well-de- 
served miseries. 

The  most  ridiculous  element  of  such  an  exhibition  is 
the  complacent  self-delusion  of  the  victims.  They  believe 
that  their  idol  bestows  upon  them  an  amount  of  comfort 
unknown  to  other  people,  that  it  affords  the  most  per- 
fect and  salubrious  ventilation,  and,  above  all,  that  it  is  a 
"cheerful"  institution.  The  "cheerfulness"  is,  perhaps, 


"  THE  ENGLISHMAN'S  FIRESIDE."  215 

the  broadest  part  of  the  whole  caricature,  especially  when  we 
consider  that,  according  to  this  theory  of  the  cheerfulness 
of  fire-gazing,  the  16-inch  idiot  must  be  the  most  cheerful 
of  all  human  beings. 

The  notion  that  our  common  fireplaces  and  chimneys  af- 
ford an  efficient  means  of  ventilation,  is  almost  too  absurd 
for  serious  discussion.  Everybody  who  has  thought  at  all 
on  the  subject  is  aware  that  in  cold  weather  the  exhalations 
of  the  skin  and  lungs,  the  products  of  gas-burning,  etc., 
are  so  much  heated  when  given  off  that  they  rise  to  the 
upper  part  of  the  room  (especially  if  any  cold  outer  air  is 
admitted),  and  should  be  removed  from  there  before  they 
cool  again  and  descend.  Now,  our  fireplace  openings  are 
just  where  they  ought  not  to  be  for  ventilation;  they  are  at 
the  lower  part  of  the  room,  and  thus  their  action  consists 
in  creating  a  current  of  cold  air  or  "draught"  from  doors 
and  windows,  which  cold  current  at  once  descends,  and 
then  runs  along  the  floor,  chilling  our  toes  and  provoking 
chilblains. 

This  cold  fresh  air  having  done  its  worst  in  the  way  of 
making  us  uncomfortable,  passes  directly  up  the  chimney 
without  doing  us  any  service  for  purposes  *of  respiration. 
Our  mouths  are  usually  above  the  level  of  the  chimney 
opening,  and  thus  we  only  breathe  the  vitiated  atmosphere 
which  it  fails  to  remove. 

Not  only  does  the  fire-opening  fail  to  purify  the  air  we 
breathe,  it  actually  prevents  the  leakage  of  the  lower  part 
of  the  windows  and  doors  from  assisting  in  the  removal  of 
the  upper  stratum  of  vitiated  air,  for  the  strong  up-draught 
of  the  chimney  causes  these  openings  to  be  fully  occupied 
by  an  inflowing  current  of  cold  air,  which  at  once  de- 
scends, and  then  proceeds,  as  before  stated,  to  the  chimney. 
If  the  leakage  is  insufficient  to  supply  the  necessary  amount 
of  chilblain-making  and  bronchitis-producing  draught,  it 
has  to  enter  by  way  of  the  chimney-pot  in  the  form  of  oc- 
casional spasms  of  down-draught,  accompanied  by  gusts  of 
choking  and  blackening  smoke.  It  is  a  fact  not  generally 
known,  that  smoky  chimneys  are  especial  English  institu- 
tions, one  of  the  peculiar  manifestations  of  our  very  supe- 
rior domestic  comfortableness. 


216  SCIENCE  IN  SHORT  CHAPTERS. 

It  is  true  that,  in  some  of  our  rooms,  an  Arnott's  ven- 
tilator opens  into  the  upper  part  of  the  chimney,  but  this 
was  intended  by  Dr.  Arnott  as  an  adjunct  to  his  modifica- 
tion of  the  German  stove,  and  such  ventilator  can  only  act 
efficiently  where  a  stove  is  used.  The  pressure  required  to 
fairly  open  it  can  only  be  regularly  obtained  when  the 
chimney  is  closed  below,  or  its  lower  opening  is  limited  to 
that  of  a  stovepipe. 

The  mention  of  a  German  stove  has  upon  an  English 
fire-worshiper  a  similar  effect  to  the  sight  of  water  upon  a 
mad  dog.  Again  and  again,  when  I  have  spoken  of  the 
necessity  of  reforming  our  fireplaces,  the  first  reply  eli- 
cited has  been,  "  What,  would  you  have  us  use  German 
stoves?"  In  every  case  where  I  have  inquired  of  the  ex- 
claimer,  "  What  sort  of  a  thing  is  a  German  stove?"  the 
answer  has  proved  that  the  exclamation  was  but  a  manifes- 
tation of  blind  prejudice  based  upon  total  ignorance.  These 
people  who  are  so  much  shocked  at  the  notion  of  introduc- 
ing-" German  stoves"  have.no  idea  of  the  construction  of 
the  stoves  which  deservedly  bear  this  title.  Their  notion 
of  a  German  stove  is  one  of  those  wretched  iron  boxes  of 
purely  English  invention  known- to  ironmongers  as  "shop 
stoves."  These  things  get  red  hot,  their  red-hot  surface 
frizzles  the  dust  particles  that  float  in  the  atmosphere  and 
perfume  the  apartment  accordingly.  This,  however  dis- 
agreeable, is  not  very  mischievous,  perhaps  the  reverse,  as 
many  of  these  dust  particles,  which  are  revealed  by  a  sun- 
beam, are  composed  of  organic  matter  which,  as  Dr.  Tyn- 
dall  argues,  may  be  carriers  of  infection.  If  we  must 
inhale;  such  things,  it  is  better  that  we  should  breathe  them 
cooked  than  take  them  raw. 

The  true  cause  of  the  headaches  and  other  mischief  which 
such  stoves  unquestionably  induce  is  very  little  understood 
in  this  country.  It  has  been  falsely  attributed  to  over- 
drying  of  the  atmosphere,  and  accordingly  evaporating 
pans  and  other  contrivances  have  been  attached  to  such 
stoves,  but  with  little  or  no  advantage.  Other  explana- 
tions are  given,  but  the  true  one  is  that  iron  when  red  hot 
is  permeable  by  carbonic  oxide.  This  was  proved  by  the  re- 
searches of  Professor  Graham,  who  showed  that  this  gas 


"  THE  ENGLISHMAN'S  FIRESIDE."  217 

not  only  can  pass  through  red-hot  iron  with  singular  facil- 
ity, but  actually  does  so  whenever  there  is  atmospheric  air 
on  one  side  and  carbonic  oxide  on  the  other. 

For  the  benefit  of  my  non-chemical  readers.  I  may  explain 
that  when  any  of  our  ordinary  fuel  is  burned  there  are  two 
products  of  carbon  combustion,  one  the  result  of  complete 
combustion,  the  other  of  semi-combustion — carbonic  acid 
and  carbonic  oxide — the  former,  though  suffocating  when 
breathed  alone  or  in  large  proportion,  is  not  otherwise  poi- 
sonous, and  has  no  disagreeable  odor;  it  is  in  fact  rather 
agreeable  in  small  quantities,  being  the  material  of  cham- 
pagne bubbles  and  of  those  of  other  effervescing  drinks. 
Carbonic  oxide,  the  product  of  semi-combustion,  is  quite 
different.  Breathed  only  in  small  quantities,  it  acts  as  a 
direct  poison,  producing  peculiarly  oppressive  headaches. 
Besides  this,  it  has  a  disagreeable  odor.  It  thus  resembles 
many  other  products  of  imperfect  combustion,  such  as  those 
which  are  familiar  to  everbody  who  has  ever  blown  out  a 
tallow  candle,  and  left  the  red  wick  to  its  own  devices. 

On  this  account  alone  any  kind  of  iron  stove  capable  of 
becoming  red-hot  should  be  utterly  condemned.  If  Eng- 
lishmen did  their  traveling  in  North  Europe  in  the  winter, 
their  self-conceit  respecting  the  comfort  of  English  houses 
would  be  cruelly  lacerated,  and  none  such  would  perpetrate 
the  absurdity  of  applying  the  name  of  "  German  stove"  to 
the  iron  fire-pots  that  are  sold  as  stoves  by  English  iron- 
mongers. 

As  the  Germans  use  so  great  a  variety  of  stoves,  it  is 
scarcely  correct  to  apply  the  title  of  German  to  any  kind  of 
stove,  unless  we  limit  ourselves  to  North  Germany.  There, 
and  in  Sweden,  Denmark,  Norway,  and  Russia,  the  con- 
struction of  stoves  becomes  a  specialty.  The  Russian 
stove  is  perhaps  the  most  instructive  to  us,  as  it  affords  the 
greatest  contrast  to  our  barbarous  device  of  a  hole  in  the 
wall  into  which  fuel  is  shoveled,  and  allowed  to  expend 
nine-tenths  of  its  energies  in  heating  the  clouds,  while  only 
the  residual  ten  per  cent  does  anything  towards  warming 
the  room.  With  the  thermometer  outside  below  zero,  a 
house  in  Moscow  or  St.  Petersburg  is  kept  incomparably 
more  warm  and  comfortable,  and  is  letter  ventilated  (though, 


218  SCIENCE  IN  SHORT  CHAPTERS. 

perhaps,  not  so  much  ventilated)  than  a  corresponding  class 
of  house  in  England,  where  the  outside  temperature  is  20 
or  30  degrees  higher,  and  this  with  a  consumption  of  about 
one-fourth  of  the  fuel  which  is  required  for  the  production 
of  British  bronchitis. 

This  is  done  by,  first  of  all,  sacrificing  the  idiotic  recrea- 
tion of  fire-gazing,  then  by  admitting  no  air  into  the  chim- 
ney but  that  which  is  used  for  the  combustion  of  the  fuel; 
thirdly,  by  sending  as  little  as  possible  of  the  heat  up  the 
chimney;  fourthly,  by  storing  the  heat  obtained  from  the 
fuel  in  a  suitable  reservoir,  and  then  allowing  it  gradually 
and  steadily  to  radiate  into  the  apartment  from  a  large  but 
not  overheated  surface. 

TheKussian  stove  by  which  these  conditions  are  fulfilled 
is  usually  an  ornamental,  often  a  highly  artistic,  handsome 
article  of  furniture,  made  of  fire-resisting  porcelain,  glazed 
and  otherwise  decorated  outside.  Internally  it  is  divided 
by  thick  fire-clay  walls  into  several  upright  chambers  or 
flues,  usually  six.  Some  dry  firewood  is  lighted  in  a  suit- 
able fireplace,  and  is  supplied  with  only  sufficient  air  to  ef- 
fect combustion,  all  of  which  enters  below  and  passes  fairly 
through  the  fuel.  The  products  of  combustion  being  thus 
undiluted  with  unnecessary  cold  air,  are  very  highly  heated, 
and  in  this  state  pass  up  compartment  or  flue  No.  1;  they 
are  then  deflected,  and  pass  down  No.  2;  then  up  No.  3, 
then  down  No.  4,  then  up  No.  5,  then  down  No.  6.  At  the 
end  of  this  long  journey  they  have  given  up  most  of  their 
heat  to  the  24  heat-absorbing  surfaces  of  the  fire-clay  walls 
of  the  six  flues. 

When  the  interior  of  the  stove  is  thus  sufficiently  heated, 
the  fire-door  and  the  communication  with  the  chimney  are 
closed,  and  the  fire  is  at  once  extinguished,  having  now 
done  its  day's  work  ;  the  interior  of  the  stove  has  bottled 
up  its  calorific  force,  and  holds  its  ready  fore  mission  into  the 
apartment.  This  is  effected  by  the  natural  properties  of 
the  walls  of  the  earthenware  reservoir.  They  are  bad  con- 
ductors and  good  radiators.  The  heat  slowly  passes  through 
to  the  outside  of  the  stove,  is  radiated  into  the  apartment 
from  a  large  and  moderately-heated  surface,  which  affords 
a  genial  and  well-diffused  temperature  throughout. 


"  THE  ENGLISHMAN'S  FIRESIDE."  '219 

There  is  no  scorching  in  one  little  red- hot  hole,  or  cor- 
ner, or  box,  and  freezing  in  the  other  parts  of  the  room. 
There  are  no  draughts,  as  the  chimney  is  quite  closed  as 
soon  as  the  heat  reservoir  is  supplied.  If  one  of  these 
heat  reservoirs  is  placed  in  the  hall,  where  it  may  form  a 
noble  ornament  and  can  easily  communicate  with  an  under- 
ground flue,  it  warms  every  part  of  the  house,  and  enables 
the  Russian  to  enjoy  a  luxurious  temperate  climate  indoors 
in  spite  of  arctic  winter  outside. 

In  a  house  thus  warmed  and  free  from  draughts  or  blasts 
of  cold  air,  ventilation  becomes  the  simplest  of  problems. 
Nothing  more  is  required  than  to  provide  an  inlet  and  out- 
let in  suitable  places,  and  of  suitable  dimensions,  when  the 
difference  between  the  specific  gravity  of  the  cold  air  with- 
out and  warm  air  within  does  all  the  rest.  Nothing  is  easier 
to  arrange  than  to  cause  all  the  entering  air  to  be  warmed 
on  its  way  by  the  hall  stove,  and  to  regulate  the  supply 
which  each  apartment  shall  receive  from  this  general  or 
main  stream  by  adjusting  its  own  upper  outlet.  In  our 
English  houses,  with  open  chimneys,  all  such  systematic, 
scientific  ventilation  is  impossible,  on  account  of  the  domi- 
nating, interfering,  useless,  and  comfort-destroying  cur- 
rents produced  by  these  wasteful  air-shafts. 

I  should  add  that  the  Kussian  porcelain  reservoirs  may 
be  constructed  for  a  heat  supply  of  a  few  hours  or  for  a 
whole  day,  and  I  need  say  nothing  further  in  refutation  of 
the  common  British  prejudice  which  confounds  so  ad- 
mirable and  truly  scientific  a  contrivance  with  the  iron 
fire-pot  above  referred  to. 

There  is  another  kind  of  stove,  which,  for  the  sake  of 
distinction,  I  may  call  Scandinavian, -as  it  is  commonly  used 
in  Norway,  Sweden,  and  Denmark,  besides  some  parts  of 
North  Germany.  This  is  -a  tall,  hollow  iron  pillar,  of  rect- 
angular section,  varying  from  three  to  six  feet  in  width, 
and  rising  half-way  to  the  ceiling  of  the  room,  and  some- 
times higher.  A  fire  is  lighted  at  the  lower  part,  and  the 
products  of  combustion,  in  their  way  upwards,  meet  with 
horizontal  iron  plates,  which  deflect  them  first  to  the  Tight, 
then  to  the  left,  and  thus  compel  them  to  make  a  long  ser- 
pentine journey  before  they  reach  the  chimney.  By  this 


2-20  SCIENCE  IN  SHORT  CHAPTERS. 

means  they  give  off  their  heat  to  the  large  surface  of  iron 
plate,  and  enter  the  chimney  at  a  comparatively  low  tem- 
perature. The  heat  is  radiated  into  the  apartment  from 
the  large  metal  surface,  no  part  of  which  approaches  a  red- 
heat.  A  further  economy  is  commonly  effected  by  placing 
this  iron  pillar  in  the  wall  separating  two  rooms,  so  that 
one  of  its  faces  is  in  each  room.  Thus  two  rooms  are 
heated  by  one  fire.  One  of  these  may  be  the  kitchen,  and 
the  same  fire  that  prepares  the  food  may  be  used  to  warm 
the  dining-room.  The  fire-worshiper  is  of  course  de- 
prived of  his  "cheerful"  occupation  of  staring  at  the  coals, 
and  he  also  loses  his  playthings,  as  neither  poker,  tongs, 
nor  coal-scuttle  are  included  in  the  furniture  of  an  apart- 
ment thus  heated.  People  differently  constituted  consider 
that  an  escape  from  the  dust,  dirt,  and  clatter  of  these  is  a 
decided  advantage. 

Of  course  these  stoves  of  our  northern  neighbors  are 
costly — may  be  very  costly  when  highly  ornamental.  The 
stove  of  a  Norwegian  "bonder,"  or  peasant  proprietor, 
costs  nearly  half  as  much  as  the  two-roomed  wooden  house 
in  which  it  is  erected,  but  the  saving  it  effects  renders  it 
a  good  investment.  It  would  cost  100?.  or  200/.  to  fit  up 
an  English  mansion  with  suitable  porcelain  stoves  of  the 
Eussian  pattern,  but  a  saving  of  201.  a  year  in  fuel  would 
yield  a  good  return  as  regards  mere  cost,  while  the  gain  in 
comfort  and  healthfulness  would  be  so  great  that,  once  en- 
joyed and  understood, such  outlay  would  be  willingly  made  by 
all  who  could  afford  it,  even  if  no  money  saving  were  effected. 

Only  last  week  I  was  discussing  this  question  in  a  rail- 
way carriage,  where  one  of  my  fellow-passengers  was  an 
intelligent  Holsteiner.  He  confirmed  the  heresy  by  which 
I  had  shocked  the  others,  in  exulting  in  the  high  price  of 
coal,  and  wishing  it  to  continue.  He  told  us  that  when 
wood  was  abundant  in  his  country,  fuel  was  used  as  bar- 
barously, as  wastefully,  and  as  inefficiently  as  it  now  is 
here,  but  that  the  diforesting  of  the  land,  and  the  great 
cost  of  fuel,  forced  upon  them  a  radical  reform,  the  result 
of  which  is  that  they  now  have  their  houses  better  warmed, 
and  at  a  less  cost  than  when  fuel  was  obtainable  at  one 
fourth  of  its  present  cost. 


"BAILT8  BEADS."  221 

Such  will  be  the  case  with  us  also  if  we  can  but  main- 
tain the  present  coal  famine  during  one  or  two  more  Avin- 
ters,  especially  if  we  should  have  the  further  advantage  of 
some  very  severe  weather  in  the  meantime.  Hence  the 
cruel  wishes  above  expressed.  The  coal  famine  would 
scarcely  be  necessary  if  we  had  Kussian  winters,  for  in  such 
case  our  houses,  instead  of  being  as  they  are,  merely  the 
most  uncomfortable  in  North  Europe,  would  be  quite 
uninhabitable.  With  our  mild  winters  we  require  the  ut- 
most severity  of  fuel  prices  to  civilize  our  warming  and 
ventilating  devices. 


"BAILY'S  BEADS." 

TO  THE   EDITOR   OF  THE    Times. 

SIB, — The  curious  breaking  up  of  the  thin  annular  rim 
of  the  sun  which  is  uncovered  just  before  and  just  after 
totality,  or  which  surrounds  the  moon  during  an  annular 
eclipse,  has  been  but  occasionally  observed,  and  some  scep- 
ticism as  to  the  accuracy  of  Baily's  observations  has  lately 
arisen.  Having  attempted  an  explanation  of  the  "beads," 
I  have  looked  with  much  interest  for  the  reports  of  the 
eclipse  of  1870,  for,  if  I  am  right,  they  ought  to  have  been 
well  seen  on  this  occasion.  This  has  been  the  case.  We 
are  informed  that  both  Lord  Lindsay  and  the  Rev.  S.  J. 
Perry  have  observed  them,  and  that  Lord  Lindsay  has  set 
aside  all  doubts  respecting  their  reality  by  securing  a  photo- 
graphic record  of  their  appearance. 

My  explanation  is  that  they  are  simply  sun-spots  seen  in 
profile — spots  just  caught  in  the  fact  of  turning  the  sun's 
edge.  All  observers  are  now  agreed  as  to  the  soundness  of 
Galileo's  original  description  of  the  spots — that  they  are 
huge  cavities,  great  rifts  of  the  luminous  surface  of  the 
sun,  many  thousands  of  miles  in  diameter,  and  probably 
some  thousand  miles  deep.  Let  us  suppose  the  case  of  a 
spot — say,  2,000  miles  deep  and  10,000  miles  across  (Sir 
W.  Herschel  has  measured  spots  of  50,000  miles  diameter). 


222  SCIENCE  IN  SHORT  CHAPTERS. 

When  such  a  spat  in  the  course  of  the  sun's  rotation  reaches 
that  part  which  forms  the  visible  edge  of  the  sun,  it  must, 
if  rendered  visible,  be  seen  as  a  notch;  but  what  will  be 
the  depth  of  such  a  notch?  Only  about  1-4.3'Oth  of  the 
sun's  diameter.  But  the  apparent  depth  would  be  much 
less  as  the  edge  or  rim  of  the  spot  next  to  the  observer 
would  cut  off  more  or  less  of  its  actually  visible  depth,  this 
amount  depending  upon  the  lateral  or  east  and  west  dia- 
meter of  the  spot  and  its  position  at  the  time  of  observa- 
tion. 

Thus,  the  visible  depth  of  such  a  notch  would  rarely  ex- 
ceed one  thousandth  of  the  sun's  apparent  diameter,  or 
might  be  much  less.  The  sun  being  globular,  the  edge 
which  is  visible  to  us  is  but  our  horizon  of  his  fiery  ocean, 
which  we  see  athwart  the  intervening  surface  as  it  gradually 
bends  away  from  our  view.  So  small  an  indent  upon  this 
edge  would,  under  ordinary  circumstances  of  observation, 
be  rendered  quite  invisible  by  the  irradiation  of  the  vast 
globular  surface  of  the  glaring  photosphere,  upon  which  it 
would  visually  encroach. 

If,  however,  this  body  of  glare  could  be  screened  off,  and 
only  a  line  of  the  sun's  edge,  less  than  one  thousandth  of 
his  diameter,  remain  visible,  the  notch  would  appear  as  a 
distinct  break  in  this  curved  line  of  light.  If  a  group  of 
spots,  or  a  great  irregular  spot  with  several  umbrae,  were  at 
such  a  time  situated  upon  the  sun's  edge,  the  appearance  of 
a  series  of  such  notches  or  breaks  leaving  intermediate  de- 
tachments of  the  visible  ring  of  the  photosphere  would  be 
the  necessary  result,  and  thus  would  be  presented  exactly 
the  appearance  described  as  "Baily's  beads." 

I  have  been  led  to  anticipate  a  display  of  these  beads 
during  the  late  eclipse  by  the  fact  that  some  days  preceding 
it  a  fine  group  or  spots — visible  to  the  naked  eye  through 
a  London  fog — were  traveling  towards  the  eastern  edge  of 
the  sun,  and  should  have  reached  the  limb  at  about  the 
time  of  the  eclipse.  The  beads  were  observed  by  the  Rev. 
S.  J.  Perry  just  where  I  expected  them  to  appear.  I  have 
not  yet  learnt  on  which  side  of  the  sun  they  were  observed 
and  photographed  by  Lord  Lindsay. 

Baily's  first  observation  of  the  beads  was  made  during 


THE  COLORING   OF  GREEN  TEA.  223 

the  annular  eclipse  of  May  15, 1836.  That  year,  like:  1870, 
was  remarkable  for  a  great  display  of  sun-spots.  As  in 
1870,  they  were  then  visible  to  the  naked  eye.  I  well  re- 
member my  own  boyish  excitement  when,  a  few.  weeks  be- 
fore the  eclipse  of  1836,  I  discovered  a  spot  upon  the  red- 
dened face  of  the  setting  sun — a  thing  I  had  read  about, 
and  supposed  that  only  great  astronomers  were  privileged 
to  see.  The  richness  of  this  sun-spot  period  is  strongly 
impressed  on  my  memory  by  the  fact  that  I  continued 
painfully  watching  the  dazzling  sun,  literally  "watching 
and  weeping,"  up  to  the  Sunday  of  the  eclipse,  on  which 
day  also  I  saw  a  large  spot  through  my  bit  of  smoked 
glass. 

The  previous  records  of  these  appearances  of  fracture  of 
the  thin  line  of  light  are  those  of  Halley,  in  his  memoir  on 
the  total  eclipse  of  1715,  and  Maclauren's  on  that  of  1737. 
Both  of  these  correspond  to  great  spot  periods;  the  inter- 
vals between  1715,  1737,  1836,  and  1870  are  all  divisible  by 
eleven.  The  observed  period  of  sun-spot  occurrence  is 
eleven  years  and  a  small  fraction. 

I  am  anxiously  awaiting  the  arrival  of  Lord  Lindsay's 
long-exposure  photographs  of  the  corona,  for  if  they  repre- 
sent the  varying  degrees  of  splendor  of  this  solar  append- 
age, the  explanations  offered  in  Chapter  xii.  of  my  essay  on 
"  The  Fuel  of  the  Sun"  will  be  very  severely  tested"  by  them. 
Yours  respectfully, 

W.  MATTIEU  WILLIAMS. 

Woodside  Green,  Croydon,  January  4,  1871. 


THE  COLORING  OF  GREEN  TEA. 

THE  following  is  a  copy  of  my  report  to  the  Grocer  on 
a  sample  of  the  ingredients  actually  used  by  the  Chinese  for 
coloring  of  tea,  which  sample  was  sent  to  the  Grocer 
office  by  a  reliable  correspondent  at  Shanghai  (November, 
1873).  I  reprint  it  because  the  subject  has  a  general  inte- 
rest and  is  commonlv  misunderstood: 


224  SCIENCE  IN  SHORT  CHAPTERS. 

I  have  examined  the  blue  and  the  yellowish-white 
powders  received  from  the  office,  and  find  that  the  blue  is 
not  indigo,  as  your  Shanghai  correspondent  very  naturally 
supposes,  but  is  an  ordinary  commercial  sample  of  Prussian 
blue.  It  is  not  so  bright  as  some  of  our  English  samples, 
and  by  mere  casual  observation  may  easily  be  mistaken  for 
indigo.  Prussian  blue  is  a  well-known  compound  of  iron, 
cyanogen,  and  potassium.  Commercial  samples  usually  con- 
tain a  little  clayey  or  other  earthy  impurities,  which  is  the 
case  with  this  Chinese  sample.  There  are  two  kinds  of 
Prussian  blue  —  the  insoluble,  and  the  basic  or  soluble. 
The  Chinese  sample  is  insoluble. 

This  is  important,  seeing  that  we  do  not  eat  our  tea- 
leaves,  but  merely  drink  an  infusion  of  them;  and  thus  even 
the  very  small  quantity  which  faces  the  tea-leaf  remains 
with  the  spent  leaves,  and  is  not  swallowed  by  the  tea- 
drinker,  who  therefore  need  have  no  fear  of  being  poisoned 
by  this  ornamental  adulterant. 

Its  insolubility  is  obvious,  from  the  fact  that  green  tea 
does  not  give  a  blue  infusion,  which  would  be  the  case  if 
the  Prussian  .blue  were  dissolved. 

There  are  some  curious  facts  bearing  on  this  subject  and 
connected  with  the  history  of  the  manufacture  of  Prussian 
blue.  Messrs.  BramwellTof  Newcastle-on-Tyne,  who  may 
be  called  the  fathers  of  this  branch  of  industry,  established 
their  works  about  a  century  ago.  It  was  first  sold  at  two 
guineas  per  lb.;  in  1815  it  had  fallen  to  10s.  6d.,  in  1820  to 
"2s.  6d.,  then  down  to  Is.  9(7.  in  1850.  I  see  by  the  Price 
Current  of  the  Oil  Trade  Review  that  the  price  has  re- 
cently been  somewhat  higher. 

In  the  early  days  of  the  trade  a  large  portion  of  Messrs. 
Bramweli's  produce  was  exported  to  China,  The  Chinese 
then  appear  to  have  been  the  best  customers  of  the  British 
manufacturers  of  this  article.  Presently,  however,  the 
Chinese  demand  entirely  ceased,  and  it  was  discovered  that 
a  common  Chinese  sailor,  who  had  learned  something  of 
the  importation  of  this  pigmet  to  his  native  country,  came 
to  England  in  an  East  Indiaman,  visited,  or  more  probably 
obtained  employment  at  a  Prussian  blue  manufactory, 
learned  the  process,  and,  on  his  return  to  China,  started 


THE  COLORING   OF  GREEN  TEA.  225 

there  a  manufactury  of  his  own,  which  was  so  successful 
that  in  a  short  time  the  whole  of  the  Chinese  demand  was 
supplied  by  native  manufacture;  and  thus  ended  our  export 
trade.  Those  who  think  the  Chinese  are  an  unteachable 
and  unimprovable  people  may  reflect  on  this  little- history. 

The  yellowish  powder  is  precisely  what  your  Shanghai 
correspondent  supposes.  It  is  steatite,  or  "soapstoue." 
This  name  is  very  deceptive,  and  coupled  with  the  greasy 
or  unctuous  feel  of  the  substance,  naturally  leads  to  the 
supposition  that  it  is  really  as  it  appears,  an  oleaginous 
substance.  This,  however,  is  not  the  case.  It  is  a  com- 
pound of  silicia,  magnesia,  and  water,  with  which  are 
sometimes  associated  a  little  clay  and  oxide  of  iron.  Like 
most  magnesian  minerals,  it  has  a  curiously  smooth  or 
slippery  surface,  and  hence  its  name.  It  nearly  resembles 
meerschaum,  the  smoothness  of  which  all  smokers  under- 
stand. 

When  soapstone  is  powdered  and  rubbed  over  a  moder- 
ately rough  surface,  it  adheres,  and  forms  a  shining  film; 
just  as  another  unctuous  mineral,  graphite  (the  "  black- 
lead"  of  the  housemaid),  covers  and  polishes  ironwork. 
On  this  account,  soapstone  is  used  in  some  lubricating  com- 
pounds, for  giving  the  finishing  polish  to  enameled  cards, 
and  for  other  similar  purposes. 

With  a  statement  of  these  properties  before  us,  and  the 
interesting  description  of  the  process  by  your  Shanghai  cor- 
respondent, the  whole  riddle  of  green-tea  coloring  and  fac- 
ing is  solved.  The  Prussian  blue  and  soapstone  being  mixed 
together  when  dry  in  the  manner  described,  the  soapstone 
adheres  to  the  surface  of  the  particles  of  blue,  and  imparts 
to  them  not  only  a  pale  greenish  color,  but  also  its  own 
unctuous,  adhesive,  and  polishing  properties.  The  mixture 
being  well  stirred  in  with  the  tea-leaves,  covers  them  with 
this  facing,  and  thus  gives  both  the  color  and  peculiar 
pearly  lustre  characteristic  of  some  kinds  of  green  tea.  I 
should  add  that  the  soopstone,  like  the  other  ingredient,  is 
insoluble,  and  therefore  perfectly  harmless. 

Considering  the  object  to  be  attained,  it  is  evident  from 
the  above  that  John  Chinaman  understands  his  business, 
and  needs  no  lessons  from  European  chemists.  It  would 


226  SCIENCE  IN  SHORT  CHAPTERS. 

puzzle  all  the  Fellows  of  the  Chemical  Society,  though  they 
combined  their  efforts  for  the  purpose,  to  devise  a  more 
effective,  cheap,  simple,  and  harmless  method  of  satisfying 
the  foolish  demand  for  unnaturally  colored  tea-leaves. 

When'the  tea-drinking  public  are  sufficiently  intelligent 
to  prefer  naturally  colored  leaves  to  the  ornamental  stuff 
they  now  select,  Mr.  Chinaman  will  assuredly  be  glad 
enough  to  discontinue  the  addition  of  the  Prussian  blue, 
which  costs  him  so  much  more  per  pound  than  his  tea- 
leaves,  and  will  save  him  the  trouble  of  the  painting  and 
varnishing  now  in  demand. 

In  the  meantime,  it  is  satisfactory  to  know  that,  although 
a  few  silly  people  may  be  deceived,  nobody  is  poisoned  by 
this  practice  of  coloring  green  tea.  I  say  "  a  few  silly  peo- 

Sle,"  for  there  can  be  only  a  few,  and  those  very  silly  in- 
eed,  who  judge  of  their  tea  by  its  appearance  rather  than 
by  the  quality  of  the  infusion  it  produces. 

With  these  facts  before  us  it  is  not  difficult  to  trace  the 
origin  of  the  oft-repeated  and  contradicted  statement  that 
copper  is  used  in  coloring  green  tea.  One  of  the  essential 
ingredients  in  the  manufacture  of  Prussian  blue  is  sulphate 
of  iron,  the  common  commercial  name  which  is  "green 
copperas."  It  is  often  supposed  to  contain  copper,  but  this 
is  not  the  case. 

Your  Shanghai  correspondent  overrates  the  market  value 
of  soapstone  when  he  supposes  that  Chinese  wax  may  be 
used  as  a  cheap  substitute.  In  many  places — as,  for  in- 
stance, the  "  Lizard"  district  of  Cornwall — great  veins  of 
this  mineral  occur,  which,  if  needed,  might  be  quarried  in 
vast  abundance,  and  at  very  little  cost  on  account  of  its  soft- 
ness. The  romantic  scenery  of  Kynance  Cove,  its  caverns, 
its  natural  arches,  the  "Devil's  Bellows,"  the  "Devil's 
Post-office,"  the  "Devil's  Cauldrons,"  and  other  fantastic 
formations  of  this  part  of  the  coast,  attributed  to  his  Satanic 
Majesty  or  the  Druids,  are  the  natural  results  of  the  waves 
beating  away  the  veins  of  soft  soapstone,  and  leaving  the 
deformed  skeleton  rocks  of  harder  serpentine  behind. 


IEON  FILINGS"  IN  TEA.  227 


"IRON  FILINGS"  IN  TEA. 

I  HAVE  watched  the  progress  of  the  tea  controversy  and 
the  othqr  public  performances  of  the  public  analysts  with 
considerable  interest;  it  might  have  been  with  amusement, 
but  for  the  melancholy  degradation  of  chemical  science 
which  they  involve. 

Among  the  absurdities  and  exaggerations  which  for  some 
years  past  have  been  so  industriously  trumpeted  forth  by 
the  pseudo-chemists  who  trade  upon  the  adulteration  panic 
and  consequent  demand  for  chemical  certificates  of  purity, 
the  continually  repeated  statements  concerning  the  use  of 
iron  filings  as  a  fraudulent  adulterant  of  tea  take  a  promi-  ( 
nent  place.  I  need  scarcely  remark  that,  in  order  to  form 
such  an  adulterant,  the  quantity  added  must  be  sufficiently 
great  to  render  its  addition  commercially  profitable  to  an 
extent  commensurate  with  the  trouble  involved. 

The  gentlemen  who,  since  the  passing  of  the  Adultera- 
tion Act,  have  by  some  kind  of  inspiration  suddenly  become 
full-blown  chemists,  have  certified  to  wilful  adulteration  of 
tea  with  iron  filings,  and  have  obtained  convictions  on  such 
certificates,  when,  according  to  their  own  statement,  the 
quantity  contained  has  not  exceeded  5  per  cent  in  the 
cheapest  qualities  of  tea.  Now,  the  price  of  such  tea  to  the 
Chinaman  tea-grower,  who  is  supposed  to  add  these  iron 
filings,  is  about  fourpence  to  sixpence  per  pound;  and  we 
are  asked  to  believe  that  he  will  fraudulently  deteriorate  the 
market  value  cf  his  commodity  for  the  sake  of  this  additional 
l-20th  of  weight.  Supposing  that  he  could  obtain  his  iron 
filings  at  twopence  per  pound,  his  total  gain  would  thus  be 
about  l-10th  of  a  penny  per  pound.  But  can  he  obtain 
such  iron  filings  in  the  quantity  required  at  such  a  price?  A 
little  reflection  on  a  few  figures  will  render  it  evident  that 
he  cannot,  and  that  suoh  adulteration  is  utterly  impossible. 

I  find  by  reference  to  Tlie  Grocer  of  November  8th, 
that  the  total  deliveries  of  tea  into  the  port  of  London  dur- 
ing the  first  ten  months  of  1872  were  142,429,337  Ibs.,  and 
during  the  corresponding  period  of  1873,  139,092,409  Ibs. 
Of  this  about  8£  millions  of  pounds  in  1873,  and  10  millions 


228  SCIENCE  IN,  SHORT  CHAPTERS. 

of  pounds  in  1872,  were  green,  the  rest  black.  This  gives 
in  round  numbers  about  160  millions  of  pounds  of  black  tea 
per  annum,  of  which  above  140  millions  come  from  China. 
As  the  Eussians  are  greater  tea-drinkers  than  ourselves— the 
Americans  and  British  colonists  are  at  least  equally  addicted 
to  the  beverage,  and  other  nations  consume  some  quantity — 
the  total  exports  from  China  may  be  safely  estimated  to  reach 
400  or  500  millions  of  pounds.  a 

Let  us  take  the  smaller  figure,  and  suppose  that  only  one 
fourth  of  this  is  adulterated,  ±o  the  extent  of  5  per  cent, 
with  iron  filings.  How  much  would  be  required  ?  Just  five 
millions  of  pounds  per  annum. 

It  must  be  remembered  that  coarse  filings  could  not  pos- 
sibly be  used;  they  would  show  themselves  at  once  to  the 
naked  eye  as  rusty  lamps,  and  would  shake  down  to  the 
bottom  of  the  chest;  neither  could  borings,  nor  turnings, 
nor  plane-shavings  be  used.  Nothing  but  fine  filings  would 
answer  the  supposed  purpose.  I  venture  to  assert  that  if 
the  China  tea-growers  were  to  put  the  whole  world  under 
contribution  for  their  supposed  supply  of  fine  iron  filings, 
this  quantity  could  not  be  obtained. 

Let  anyone  who  doubts  this  borrow  a  blacksmith's  vice, 
a  fine  file,  and  a  piece  of  soft  iron,  then  take  off  his  coat  and 
try  how  much  labor  will  be  required  to  produce  a  single 
ounce  of  filings,  and  also  bear  in  mind  that  fine  files  are  but 
very  little  used  in  the  manufacture  of  iron.  As  the  price  of 
a  commodity  rises  when  the  demand  exceeds  the  supply 
the  Chinaman  would  have  to  pay  far  more  for  his  adulterant 
than  for  the  leaves  to  be  adulterated.  As  Chinese  tea- 
growers  are  not  public  analysts,  we  have  no  right  to  sup- 
pose that  they  would  perpetrate  any  such  foolishness. 

The  investigations  recently  made  by  Mr.  Alfred  Bird,  of 
Birmingham,  show  that  the  iron  found  in  tea-leaves  is  not 
in  the  metallic  state,  but  in  the  condition  of  oxide;  and  he 
confirms  the  conclusions  of  Zoller,  quoted  by  Mr.  J.  A. 
Wanklyn  in  the  Chemical  News  of  October  10th— viz.,  that 
compounds  of  iron  naturally  exist  in  genuine  tea.  It  ap- 
pears, however,  that  the  ash  of  many  samples  of  black  tea 
contains  more  iron  than  naturally  belongs  to  the  plant;  and, 
accepting  Mr.  Bird's  statement,"  that  this  exists  in  the  leaf 


"IRON  FILINGS"   IN  TEA.  229 

as  oxide  mixed  with  small  siliceous  and  micaceous  particles 
I  think  we  may  find  a  reasonable  explanation  of  its  presence 
without  adopting  the  puerile  theory  of  the  adulteration 
maniac,  who,  in  his  endeavor  to  prove  that  everybody  who 
buys  or  sells  anything  is  a  swindler,  has  at  once  assumed 
the  impossible  addition  of  iron  filings  as  a  makeweight. 

In  the  first  place  we  must  remember  that  the  commodity 
in  demand  is  ''black  tea,  and  that  ordinary  leaves  dried  in  an 
ordinary  manner  are  not  black,  but  brown.  Tea-leaves, 
however,  contain  a  large  quantity  of  tannin,  a  portion  of 
which  is,  when  heated  in  the  leaves,  rapidly  convertible  into 
gallo-tannic  or  tannic  acid.  Thus  a  sample  of  tea  rich  in 
iron  would,  when  heated  in  the  drying  process,  become,  by 
the  combination  of  this  tannic  acid  with  the  iron  it  contains, 
much  darker  than  ordinary  leaves  or  than  other  teas  grown 
upon  less  ferruginous  soils  and  containing  less  iron. 

This  being  the  case,  and  a  commercial  demand  for  Uack 
tea  having  become  established,  the  tea-grower  would  natu- 
rullyseek  to  improve  the  color  of  his  tea,  especially  of  those 
samples  naturally  poor  in  iron,  and  a  ready  mode  of  doing 
this  is  offered  by  stirring  in  among  the  leaves  while  drying 
a  small  additional  dose  of  oxide  of  iron,  if  he  can  find  an 
oxide  in  such  a  form  that  it  will  spread  over  the  surface  of 
the  leaf  as  a  thin  film.  Now,  it  happens  that  the  Chinaman 
has  lying  under  his  feet  an  abundance  of  material  admirably 
adapted  for  this  purpose — viz.,  red  haematite,  some  varieties 
of  which  are  as  soft  and  unctuous  as  graphite,  and  will 
spread  over  his  tea-leaves  exactly  in  the  manner  required. 
The  micaceous  and  siliceous  particles  found  by  Mr.  Bird  are 
just  what  should  be  found  in  addition  to  oxide  of  iron,  if 
such  haematite  were  used. 

The  film  of  oxide  thus  easily  applied,  and  subjected  to 
the  action  of  the  exuding  and  decomposing  extractive  mat- 
ter of  the  heated  leaves,  would  form  the  desired  black  dye 
or  "facing." 

The  knotty  question  of  whether  this  is  or  is  nofe-an  adul- 
teration is  one  that  I  leave  to  lawyers  to  decide,  or  for 
those  debating  societies  that  discuss  such  interesting  ques- 
tions as  whether  an  umbrella  is  an  article  of  dress.  If  it 
is  an  adulteration,  and,  as  already  admitted,  is  not  at  all  in- 


230  SCIENCE  IN  SHORT  CHAPTERS. 

jurious  to  health,  then  all  other  operations  of  dyeing  are  also 
adulterations;  for  the  other  dyers,  like  the  Chinaman,  add 
certain  impurities  to  their  goods — the  silk,  wool,  or  cotton 

in  order  to  alter  their  natural  appearance,  and  to  give 

them  the.  false  facing  which  their  customers  demand,  but 
with  this  difference,  if  I  am  right  in  the  above  explanation: 
that  in  darkening  tea  nothing  more  is  done  but  to  increase 
the  proportion  of  one  of  its  natural  ingredients,  and  to  in- 
tensify its  natural  color;  while  in  the  dyeing  of  silk,  cotton, 
or  wool,  ingredients  are  added  which  are  quite  foreign  and 
unnatural,  and  the  natural  color  of  the  substance  is  alto- 
gether falsified. 

The  above  appeared  in  the  Chemical  News  November 
21,  1873,  when  the  adulteration  in  question  was  generally 
believed  to  be  commonly  perpetrated,  and  many  unfor- 
tunate shop-keepers  had  been  and  were  still  being  sum- 
moned to  appear  at  Petty  Sessions,  etc.,  and  publicly 
branded  as  fraudulent  adulterators  on  the  evidence  of  the 
newly-fledged  public  analysts,  who  confidently  asserted  that 
they  found  such  filings  mixed  with  the  tea.  Some  discus- 
sion followed  in  subsequent  numbers  of  the  Chemical  Neivs; 
but  it  only  brought  out  the  fact  that  "  finely  divided  iron" 
exists  in  considerable  quantities  in  Sheffield, — may  be 
"begged,"  as  Mr.  Alfred  H.  Allen  (an  able  analytical 
chemist,  resident  in  Sheffield,)  said.  The  fact  that  such 
finely  divided  iron  is  thus  without  commercial  value  still 
further  confirms  my  conclusion  that  it  is  not  used  for  the 
adulteration  of  tea.  If  it  were,  its  collection  would  be  a 
regular  business,  and  truck-loads  would  be  transmitted  from 
Sheffield  to  London,  the  great  centre  of  -  tea-importation. 
No_  evidence  of  any  commercial  transactions  in  iron  filings 
or  iron  dust  for  such  purposes  came  forward  in  reply  to  my 
challenge. 

The  practical  result  of  the  controversy  is  that  iron  filings 
are  no  longer  to  be  found  in  the  analytical  reports  of  the 
adulteration  of  tea. 


COS  CERT-ROOM  ACOUSTICS.  231 


COXCERT-ROOM  ACOUSTICS. 

THE  acoustics  of  public  buildings  are  now  occupying 
considerable  attention  in  London.  The  vast  audiences 
which  any  kind  of  sensational  performance  in  the  huge 
metropolis  is  capable  of  attracting,  is  forcing  the  subject 
upon  all  who  cater  for  public  amusement  or  instruction. 
There  was  probably  no  building  in  London,  or  anywhere 
else,  more  utterly  unfit  for  musical  performances  than  the 
Crystal  Palace  in  its  original  condition;  but,  nevertheless, 
the  Handel  Festival  of  last  week  was  a  great  success.  I 
attended  the  first  of  these  immense  gatherings,  and  this 
last;  but  nothing  of  the  kind  intermediate,  and,  therefore, 
am  the  better  able  to  make  comparisons. 

My  recollections  of  the  first  were  so  very  unsatisfactory 
that  I  gladly  evaded  the  grand  rehearsal  of  Friday  week, 
and  went  to  the  "  Messiah"  on  Monday  with  an  astronomi- 
cal treatise  in  my  pocket,  in  order  that  my  time  should  not 
be  altogether  wasted.  Being  seated  at  the  further  end  of 
the  transept,  in  a  gallery  above  the  level  of  the  general 
ridge-and-furrow  roof  of  the  nave,  the  plump  little  Birm- 
ingham tenor,  who  rose  to  sing  the  first  solo,  appeared, 
under  the  combined  optical  conditions  of  distance  and 
vertical  foreshortening,  like  a  chubby  cheese-mite  viewed 
through  a  binocular  microscope.  Taking  it  for  granted 
that  his  message  of  comfort  could  not  possibly  reach  my 
ear,  I  determined  to  anticipate  the  exhortation  by  settling 
down  for  a  comfortable  reading  of  a  chapter  or  two,  but  was 
surprised  to  find  I  could  hear  every  note,  both  of  recitative 
and  air. 

It  thus  became  obvious  that  the  alterations  that  have 
gradually  grown  since  the  time  when  Clara  Novello's  voice 
was  the  only  one  that  could  be  heard  across  the  trancept 
are  worthy  of  study;  that  the  advertised  success  of  the 
"velarium"  is  something  more  than  mere  puffery.  I  ac- 
cordingly used  my  eyes  as  well  as  my  ears,  and  made  a  few 
notes  which  may  be  interesting  to  musical  and  architect- 
ural, as  well  as  to  scientific  readers. 

Sound,  like  light,  heat,  and  all  other  radiations,  loses  its 


232  SCIENCE  IN  SHORT  CHAPTERS. 

intensitp  as  it  is  outwardly  dispersed,  is  enfeebled  in  the 
ratio  of  the  squares  of  distance;  thus  at  twenty  feet  from 
the  singer  the  loudness  of  the  sound  is  one  fourth  of  that 
at  ten  feet,  at  thirty  feet  one  ninth,  at  forty  feet  one  six- 
teenth, at  fifty  feet  one  twenty-fifth,  and  so  on;  that  is, 
supposing  the  singer  or  other  source  of  sound  is  surrounded 
on  all  sides  by  free,  open,  and  still  air. 

But  this  condition  is-never  fulfilled  in  practice,  except- 
ing, perhaps,  by  Simeon  Stylites  when  he  preached  to  the 
multitude  from  the  top  of  his  column.  If  Mr.  Vernon 
Eigby  had  stood  on  the  top  of  one  of  his  native  South  Staf- 
fordshire chimney-shafts,  of  the  same  height  above  the 
ground  as  the  upper  press  gallery  of  the  Crystal  Palace  is 
above  the  front  of  the  orchestra,  and  I  had  stood  on  the 
open  ground  at  the  same  distance  away  and  below  him,  his 
solo  of  "Comfort  ye,  my  People"  would  have  been  utterly 
inaudible. 

What,  then,  is  the  reason  of  this  g-reat  difference  of  effect 
at  equal  distances  ?  If  we  can  answer  this  question,  we 
shall  know  something  about  the  acoustics  of  concert- 
rooms. 

The  uninitiated  reader  will  at  one  begin  by  saying  that 
"sound  rises."  This  is  almost  universally  believed,  and 
yet  it  is  a  great  mistake,  as  commonly  understood.  Sound 
radiates  equally  in  every  direction — downwards,  upwards, 
north,  south,  east,  or  west,  unless  some  special  directive 
agency  is  used.  The  directive  agency  commonly  used  is  a 
reflecting  or  reverberating  surface. 

Thus  the  voice  of  the  singer  travels  forward  more  abun- 
dantly than  backward,  because  he  uses  the  roof,  and,  to 
some  extent,  the  walls  and  floor  of  his  mouth,  as  a  sound 
reflector.  The  root  of  his  mouth  being  made  of  concave 
plates  of  bone  with  a  thin  velarium  of  integument  stretched 
tightly  over  them,  supplies  a  model  sound  reflector;  and  I 
strongly  recommend  every  architect  who  has  to  build  a 
concert  or  lecture-room,  or  theatre,  to  study  the  roof  of  his 
own  mouth,  and  imitate  it  as  nearly  as  he' can  in  the  roof 
of  his  building. 

The  great  Italian  singing  masters  of  the  old  school,  who, 
like  the  father  of  Persian!,  could  manufacture  a  great  voice 


CONCERT-ROOM  ACOUSTICS.  233 

out  of  average  raw  material,  studied  the  physiology  of  the 
vocal  organs,  and  one  of  their  first  instructions  to  their 
pupils  was  that  they  should  sing  against  the  roof  of  the 
mouth,  then  throw  the  head 'back  and  open  the  mouth, 
so  that  the  sound  should  reverberate  forwards,  clear  of  the 
teeth  and  lips.  For  the  first  year  or  two  the  pupil  had  to 
sing  only  "la,  la,"  for  several  hours  per  day,  until  the 
faculty  of  doing  this  effectually  and  habitually  was  ac- 
quired*. 

The  popular  notion  that  sound  rises  has  probably  origin- 
ated from  the  fact  that  in  our  common  experience  the 
sounds  are  produced  near  to  some  kind  of  floor,  which  re- 
flects the  sounds  upwards,  and  thus  adds  the  reflected  sound 
to  that  which  is  directly  transmitted,  and  thereby  the  gen- 
eral result  is  materially  augmented. 

But  if  we  would  economize  sound  most  effectively,  we 
must  have  not  only  a  reflecting  floor,  but  also  a  reflecting 
roof  and  reflecting  walls  on  all  sides  of  the  concert  room. 
These  are  the  conditions  that  were  wanting  in  the  original 
structure  of  the  Crystal  Palace  transept,  for  then  the  sound 
of  the  singer's  voice  could  travel  upwards  to  that  lofty  arch 
and  sidewise  in  all  directions,  almost  as  freely  as  in  the 
open  air. 

This  defect  has  been  remedied  to  a  very  great  extent  by 
the  velarium  stretched  across  from  the  springing  of  the 
great  arch  of  glass  and  iron,  and  forming  a  ceiling,  to  the 
concert-room  part  of  the  building.  Besides  this,  a  wall  of 
drapery  is  stretched  across  each  side  of  the  transept,  and 
the  orchestra  has  its  special  walls,  roof,  and  back.  There 
are  other  minor  arrangements  for  effecting  lateral  rever- 
beration; that  is,  for  returning  the  sound  into  the  audi- 
torium proper  instead  of  allowing  it  to  wander  feebly 
througout  the  building. 

The  general  result  of  these  arrangements  is  to  render 
that  portion  of  the  building  in  which  the  reserved  seats  are 
placed  a  really  luxurious  and  efficient  concert-room,  of  mag- 
nificent proportions;  but,  very  unfortunately  and  inevitably, 
these  conditions,  which  are  so  favorable  for  the  happy  eight 
or  nine  thousand  who  can  afford  reserved  seats,  render  the 
position  of  the  other  half-dozen  thousand  outsiders  more 


234  SCIENCE  IN  SHOUT  CHAPTERS. 

disappointing  and  vexatious  than  ever.  For  my  own  part 
I  would  rather  spend  a  holiday  afternoon  in  the  mild  atmos- 
phere and  the  quiet,  soothing  gloom  of  a  coal-pit  than  be 
teased  and  irritated  by  a  strained  listening  to  the  indefinite 
roar  of  a  grand  choir,  and  the  occasional  dying  vibrations 
of  Sims  Keeves'  "top  A." 

I  have  in  the  above  advocated  reverberation  as  a  remedy 
for  diffusion  of  sound.  This  may,  perhaps,  appear  rather 
startling  to  some  musicians  who  have  a  well-founded  dread 
of  echoes,  and  who  read  the  words  echo  and  reverberation 
as  synonymous.  This  requires  a  little  explanation.  As 
light  is  transmitted,  reflected,  and  absorbed  in  the  same 
manner  as  sound,  and  as  light  is  visible — or,  rather,  renders 
objects  visible — I  will  illustrate  my  meaning  by  means  of 
light. 

Let  us  suppose  three  apartments  of  equal  size  and  same 
shape,  one  having  its  walls  covered  with  mirrors,  the  second 
with  white  paper,  and  the  third  with  black  woollen  cloth, 
and  all  lighted  with  central  chandeliers  of  equal  brilliancy. 
The  first  and  second  will  be  much  lighter  than  the  third, 
but  they  will  be  illuminated  very  differently. 

In  the  first,  there  will  be  a  repetition  of  chandeliers  in 
the  mirrored  walls,  each  wall  definitely  reflecting  the  image 
of  each  particular  light.  In  the  second  room  there  will  be 
reflection  also,  and  economy  of  light,  but  no  reflection  of 
definite  images;  the  apartment  will  appear  to  be  filled  with 
a  general  and  well-diffused  luminosity,  rendering  every 
object  distinctly  visible,  and  there  will  be  no  deep  shadows 
anywhere. 

In  scientific  language,  we  shall  have,  in  the  first  room, 
regular  reflection;  in  the  second,  scattering  reflection;  in 
the  third  room  we  should  have  comparative  gloom,  owing 
to  the  absorption  of  the  light  by  the  black  cloth. 

We  may  easily  suppose  the  parallels  of  these  in  the  case 
of  sound.  If  the  velarium  and  side  walls  of  the  transept 
and  orchestra  were  made  of  sheet  iron,  or  smooth,  bare, 
unbroken  vibrating  wooden  boards,  we  should  have  a  cer- 
tain amount  of  regular  reflection  of  sound  or  echo.  Just 
as  we  should  see  the  particular  lights  of  the  chandelier 
reflected  in  the  first  room,  so  should  we  hear  the  particular 


CONCERT-ROOM  ACOUSTICS.  235 

notes  of  the  singer  or  player  echoed  by  such  regularly 
vibrating  walls  and  ceiling. 

If,  again,  the  velarium  and  side  drapery  of  the  transept 
and  orchestra  had  been  thick,  soft  woollen  cloths,  the 
sound,  like  the  light,  would  have  been  absorbed  or  "muf- 
fled," and,  though  very  clear,  it  would  be  weak  and  insuf- 
ficient. 

The  reader  will  now  ask — What,  then,  is  the  right  ma- 
terial for  such  velarium  and  walls?  I  cannot  pretend  to 
say  what  is  the  best  possible,  believing  that  it  has  yet  to  be 
discovered.  The  best  yet  known,  and  attainable  at  moder- 
ate expense,  is  common  canvas  or  calico,  washed  or  painted 
over  with  a  mixture  of  size  and  lime,  or  other  attainable 
material  that  will  fill  up  the  pores  of  the  fabric,  and  give  it 
a  moderately  smooth  face  or  surface.  Thus  prepared,  it  is 
found  to  reflect  sound,  as  paper,  ground  glass,  etc.,  reflect 
light,  by  scattering  reverberation,  •  but  without  definite 
echo. 

It  will  now  be  understood  how  the  velarium  acted  in 
rendering  the  solos  so  clearly  audible  at  the  great  height 
and  distance  of  the  Upper  Press  Gallery.  Instead  of  being 
wasted  by  diffusion  in  the  great  vault  above,,  they  were 
stopped  and  reflected  by  the  velarium,  but  not  so  reflected 
as  to  produce  disagreeable  repetition  notes,  just  audible  at 
particular  points,  as  the  lights  of  the  mirror  reflections  of 
the  chandeliers  would  be. 

Flat  surfaces  reflect  radially,  while  concave  surfaces  with 
certain  curves  reflect  sound,  light,  heat,  etc.,  in  parallel 
lines.  The  walls  and  roof  of  a  music-hall  should  scatter 
their  reflections  on  all  sides,  and,  therefore,  should  be  flat, 
or  nearly  so,  excepting  at  the  angles,  which  should  be 
curved  or  hollowed.  From  the  orchestra  the  sound  is 
chiefly  required  to  be  projected  forward  as  from  the  singers 
mouth;  and,  therefore,  an  orchestra  should  have  curved 
walls  and  roof. 

Space  will  not  permit  a  dissertation  here  on  the  particu- 
lar curv,3  required.  This  has,  I  believe,  been  carefully 
calculated  in  constructing  the  Crystal  Palace  orchestra. 
Viewed  from  a  distance,  the  whole  orchestra  is  curiously 
like  a  huge  wide-opened  mouth  that  only  requires  to  close 


236  SCIENCE  IN  SHOUT  CHAPTERS. 

a  little  and  open  a  little  more,  according  to  the  articula- 
tions of  the  choir,  to  represent  the  vocal  effort  of  one 
gigantic  throat. 

There  is,  I  think,  one  fault  in  the  shape  of  this  mouth. 
It  extends  too  far  laterally  in  proportion  to  its  perpendicu- 
lar dimensions.  The  angles  of  the  mouth  are  too  acute; 
the  choir  extends  too  far  on  each  side.  The  singers  should 
be  packed  more  like  those  of  the  Birmingham  Festival 
Choir. 

There  is  an  acoustic  limit  to  the  magnitude  of  choirs. 
Sound  travels  at  about  1100  feet  per  second,  and  thus,  if 
one  of  the  singers  of  a  choir  is  110  feet  nearer  than  another 
singer  to  any  particular  auditor,  the  near  singer  will  be 
heard  one-tenth  of  a  second  before  the  more  distant,  though 
they  actually  sing  exactly  together.  In  rapid  staccato 
passages  this  would  produce  serious  confusion,  though  in 
such  music  as  most  of  Handel's  it  would  be  scarcely 
observable. 

Some  observations  which  I  have  made  convince  me  that 
the  actual  choir  of  the  Handel  Festivals  has  reached,  if  not 
exceeded,  the  acoustic  limits  even  for  Handel's  music,  and 
decidedly  exceeds  the  limits  permissible  for  Mendelsshon 
and  most  other  composers. 

1  found  that  when  standing  on  the  floor  of  the  building 
in  front  of  the  orchestra,  and  on  one  side,  I  could  plainly 
distinguish  the  wave  of  difference  of  time  due  to  the  travel- 
ing of  the  sound,  and  in  all  the  passages  which  required 
to  be  taken  up  smartly  and  simultaneously  by  the  opposite 
sides  of  the  choir,  the  effect  was  very  disagreeable. 

The  defect,  however,  was  not  observable  from  the  press 
gallery,  which  is  placed  as  nearly  as  may  be  to  the  focus  of 
the  orchestral  curve,  so  that  radial  lines  drawn  from  the 
auditor  to  different  parts  of  the  orchestra  do  not  differ  so 
much  in  length  as  to  effect  perceptible  differences  in  the 
moment  at  which  the  different  sounds  reach  the  ear. 

My  conclusion,  therefore,  is  that  if  any  amendment  is  to 
be  made  in  the  numbers  of  the  Handel  Festival  choir,  it 
should  rather  be  done  by  a  reduction  than  an  increase;  that 
the  four  thousand  voices  should  rather  be  reduced  to  three 
thousand  than  increased  to  five  thousand.  With  greater 


SCIENCE  AND  SPIRITUALISM:  237 

severity  of  selection  as  regards  quality,  power,  and  training 
of  each  individual  voice,  and  with  better  packing,  the  three 
thousand  would  be  more  effective  than  the  four  thousand. 


SCIENCE    AND    SPIRITUALISM. 

A  BATHER  startling  paper  in  the  current  number  of  the 
"  Quarterly  Journal  of  Science,"  from  the  pen  of  William 
Crookes,  F.R.S.  (who  is  well  known  in  the  scientific  world 
by  his  discovery  of  the  metal  thallium,  his  investigations  of 
its  properties  and  those  of  its  compounds,  besides  many 
other  important  researches,  and  also  as  the  able  and  spirited 
editor  of  the  Chemical  News),  is  now  the  subject  of  much 
scientific  gossip  and  discussion. 

Mr.  Crookes  has  for  some  time  past  been  engaged  in  in- 
vestigating some  of  the  phenomena  which  are  attributed  on 
one  hand  to  the  agency  of  spiritual  visitors,  and  on  the 
other  side  to  vulgar  conjuring.  Nobody  acquainted  with 
Mr.  Crookes  can  doubt  his  ability  to  conduct  such  an  in- 
vestigation, or  will  hesitate  for  a  moment  in  concluding 
that  he  has  done  so  with  philosophical  impartiality,  though 
many  think  it  quite  possible  that  he  may  have  been  de- 
ceived. None,  however,  can  yet  say  how. 

For  my  own  part,  I  abstain  from  any  conclusion  in  the 
meantime,  until  I  have  time  and  opportunity  to  witness  a 
repetition  of  some  of  these  experiments,  and  submitting 
them  to  certain  tests  which  appear  to  me  desirable.  Though 
struggling  against  a  predisposition  to  prejudge,  and  to  con- 
clude that  the  phenomena  are  the  results  of  some  very  skillful 
conjuring,  I  very  profoundly  respect  the  moral  courage  that 
Mr.  Crookes  has  displayed  in  thus  publicly  grappling  with 
a  subject  which  has  been  soiled  by  contact  with  so  many 
dirty  fingers.  Nothing  but  a  pure  love  of  truth,  overpow- 
ering every_  selfish  consideration,  could  have  induced  Mr. 
Crookes  to  imperil  his  hard-earned  scientific  reputation  by 
stepping  thus  boldly  on  such  very  perilous  ground. 

It  is  only  fair,  at  the  outset,  to  state  that  Mr.  Crookes  is 


238  SCIENCE  IN  SHORT  CHAPTERS. 

not  what  is  called  "  a  spiritualist.''  This  I  infer,  both  from 
what  he  has  published  and  from  conversation  I  have  had 
with  him  on  the  subject.  He  has  witnessed  some  of  the 
"  physical  manifestations,"  and,  while  admitting  that  many 
of  these  may  be  produced  by  the  jugglery  of  impostors,  he 
has  concluded  that  others  cannot  be  thus  explained;  but, 
nevertheless,  does  not  accept  the  spiritual  theory  which  at- 
tributes them  to  the  efforts  of  departed  human  souls. 

He  suspects  that  the  living  human  being  may  have  the 
power  of  exerting  some  degree  of  force  or  influence  upon 
bodies  external  to  himself — may,  for  instance,  be  able  to 
counteract  or  increase  the  gravitation  of  substances  by  an 
effort  of  the  will.  He  calls  this  power  the  "psychic  force," 
and  supposes  that  some  persons  are  able  to  manifest  it 
much  more  powerfully  than  others,  and  thus  explains  the 
performances  of  those  "mediums"  who  are  not  mere  im- 
postors. 

There  is  nothing  in  this  hypothesis  which  the  sternest, 
the  most  sceptical,  and  least  imaginative  of  physical  philos- 
ophers may  not  unhesitatingly  investigate,  provided  some 
first-sight  evidence  of  its  possibility  is  presented  to  him. 
We  know  that  the  Torpedo,  the  Gymnotus,  the  Silurus 
Electricus,  and  other  fishes,  can,  by  an  effort  of  the  will, 
act  upon  bodies  external  to  themselves.  Faraday  showed 
that  the  electric  eel  exhibited  some  years  ago  at  the  Ade- 
laide Gallery  was  able,  by  an  effort  of  its  will,  to  make  a 
magnetic  needle  suddenly  turn  thirty  degrees  aside  from  its 
usual  polar  position;  that  this  same  animal  could — still  by 
an  effort  of  will — overpower  the  gravitation  of  pieces  of  gold 
leaf,  cause  them  to  be  uplifted  and  outstretched  from  their 
pendent  position,  could  decompose  iodide  of  potassium,  and 
perform  many  other  "physical  manifestations,"  simply  by 
a  voluntary  nervous  effort,  and  without  calling  in  the  aid 
of  any  souls  of  other  departed  eels. 

Before  this  gymnotus  was  publicly  exhibited  it  was  de- 
posited at  a  French  hotel  in  the  neighborhood  of  Leicester 
Square.  A  burly  fishmonger's  man,  named  "Wren,  brought 
in  the  daily  supply  of  fish  to  the  establishment,  when  some 
of  the  servants  told  him  they  had  an  eel  so  large  that  he 
would  be  afraid  to  pick  it  up.  He  laughed  at  the  idea  of 


SCIENCE  AND  SPIRITUALISM. .  239 

being  afraid  of  an  eel,  and  when  taken  to  the  tub  boldly 
plunged  iu  both  hands  to  seize  the  fish.  A  hideous  roar 
followed  this  attempt.  Wren  had  experienced  a  demonstra- 
tion of  the  "psychic  force"  of  the  electrical  eel,  and  his 
terror  so  largely  exaggerated  the  actual  violence  of  the 
shock,  that  he  believed  for  the  remainder  of  his  life  that  he 
was  permanently  injured  by  it.  He  had  periodical  spasms 
across  the  chest,  which  could  only  be  removed  by  taking  a 
half-quartern  of  gin.  As  he  was  continually  narrating  his 
adventure  to  public-house  audiences,  and  always  had  a  spasm 
on  concluding,  which  his  hearers  usually  contributed  to  re- 
lieve, the  poor  fellow's  life  was  actually  shortened  by  the 
shock  from  the  gymnotus. 

The  experiments  which  Mr.  Crookes  relates  in  support 
of  his  psychic  force  hypothesis  are  as  follows: — In  the  first 
place  he  contrived  an  apparatus  for  testing  Mr.  Home's 
alleged  power  of  modifying  the  gravitation  of  bodies.  As 
Mr.  Home  requires  to  lay  his  hands,  or  at  least  his  finger- 
ends,  upon  the  body  to  be  influenced,  Mr.  Crookes  attached 
one  end  of  a  long  board  to  a  suspended  spring  steelyard  of 
delicate  construction;  the  other  end  of  the  board  rested  on 
a  fulcrum  in  such  a  manner  that  one  half  of  the  weight  of 
the  board  was  supported  by  the  fulcrum  and  the  other  half 
by  the  steelyard.  The  weight  of  the  board  thus  suspended 
was  carefully  noted,  and  then  Mr.  Home  put  his  fingers 
upon  that  end  of  the  board  immediately  resting  on  the  ful- 
crum in  such  a  manner  that  he  could  not  by  simple  pressure 
affect  the  dependent  end  of  the  board. 

Dr.  Huggins,  the  eminent  astronomer,  was  present,  and 
also  Serjeant  Cox,  besides  Mr.  Crookes.  They  all  watched 
Mr.  Home,  the  board,  and  the  steelyard ;  they  observed  first 
a  vibration  and  fluctuation  of  the  index,  and  finally  that 
the  steelyard  indicated  an  increase  of  weight  amounting  to 
about  three  pounds. .  Mr.  Crookes  tried  to  produce  the  same 
effect  by  mechanical  pressure  exerted  in  a  similar  manner, 
but  failed  to  do  so.  The  details  of  the  experiment  are  fully 
described  and  illustrated  by  an  engraving. 

Another  and  still  more  striking  experiment  is  described. 
Mr.  Crookes  purchased  a  new  accordion  from  Messrs. 
Wheatstone,  and  himself  constructed  a  wire  cage  open  at 


240  SCIENCE  IN  SHORT  CHAPTERS. 

top  and  bottom,  and  large  enough  for  the  accordion  to  be 
suspended  within  it  by  holding  it  over  the  open  top,  while 
the  bottom  of  the  cage  rested  on  the  floor.  The  accordion 
was  then  handed  to  Mr.  Home,  who  held  it  with  one  hand 
by  the  wooden  framework  of  the  bottom  of  the  instrument, 
as  shown  in  an  illustrative  drawing.  The  keys  were  thus 
hanging  downwards  and  the  bellows  distended  by  the 
weight  of  the  instrument  thus  pendent.  It  was  then  held 
so  that  it  should  be  entirely  surrounded  by  the  wire-work 
of  the  cage,  and  the  results  were,  as  before,  watched  keenly 
by  Mr.  Crookes,  Dr.  Huggins,  and  Serjeant  Cox.  After  a 
while  the  instrument  began  to  wave  about,  then  the  bel- 
lows contracted,  and  the  lower  part  (i.e.,  the  key-board  end) 
rose  a  little,  presently  sounds  were  produced,  and  finally 
the  instrument  played  a  tune  upon  itself  in  obedience,  as 
Mr.  Crookes  supposes,  to  the  psychic  force  which  Mr. 
Home  exerted  upon  it. 

Before  the  publication  of  the  paper  describing  these  ex- 
periments a  proof  was  sent  to  both  Dr.  Huggins  and  Ser- 
jeant Cox,  and  each  has  written  a  letter  testifying  to  its 
accuracy,  which  letters  are  printed  with  the  paper  in  the 
"Quarterly  Journal  of  Science." 

Here,  then,  we  have  the  testimony  of  an  eminent  law- 
yer, accustomed  to  sifting  evidence,  that  of  the  most  dis- 
tinguished of  experimental  astronomers,  the  man  whose 
discoveries  in  celestial  physics  have  justly  excited  the  ad- 
miration of  the  whole  civilized  world;  and  besides  these,  of 
another  Fellow  of  the  Royal  Society,  who  has  been  severely 
trained  in  "  putting  nature  to  the  torture"  by  means  of 
the  most  subtle  devices  of  the  modern  physical  and  chemi- 
cal laboratory. 

Such  testimony  must  not  be  treated  lightly.  It  would 
be  simple  impertinence  for  any  man  dogmatically  to  assert 
that  these  have  been  deceived  merely -because  he  is  uncon- 
vinced. 

Though  one  of  the  unconvinced  myself,  I  would  not  dare 
to  regard  the  investigations  of  these  gentlemen  with  any 
other  than  the  profoundest  respect.  Still  a  suggestion  oc- 
curs to  me  which  may  appear  very  brutal,  but  I  make  it 
nevertheless.  It  is  this:— That  the  testimony  of  another 


SCIENCE  AND  SPIRITUALISM.  241 

witness — of  an  expert  of  quite  a  different  school — should 
have  been  added.  I  mean  such  a  man  as  Dobler,  Houdin, 
or  the  Wizard  of  the  North.  He  might  possibly  have  de- 
tected something  which  escaped  the  scrutiny  of  the  legiti- 
mate scientific  experimentalist. 

There  is  one  serious  defect  in  the  accordion  experiment. 
The  cage  is  represented  in  the  engraving  as  placed  under  a 
table;  Mr.  Home  holds  the  instrument  in  his  hand,  which 
is  concealed  by  the  table,  and  it  does  not  appear  that  either 
Mr.  Crookes,  Dr.  Huggins,  or  Serjeant  Cox  placed  them- 
selves under  the  table  during  the  concertina  performance, 
and  thus  neither  of  them  saw  Mr.  Home's  hand.  Such,  at 
least,  appears  from  the  description  and  the  engraving.  A 
story  being  commonly  circulated  respecting  some  of  Mr. 
Home's  experiments  in  Eussia,  according  to  which  he  failed 
entirely  \vhen  a  glass  table  was  provided  instead  of  a  wooden 
one,  it  would  be  well,  if  only  in  justice  to  Mr.  Home,  to 
get  rid  of  the  table  altogether. 

It  is  very  desirable  that  these  experiments  should  be  con- 
tinued, for  two  distinct  reasons;  first,  as  a  matter  of  ordi- 
nary investigation  for  philosophical  purposes,  and,  secondly, 
as  a  means  of  demolishing  the  most  degrading  superstition 
of  this  generation. 

If  Mr.  Crookes  succeeds  in  demonstrating  the  existence 
of  the  psychic  force  and  reducing  it  to  law — as  it  must  be 
reducible  if  it  is  a  force — then  the  ground  will  be  cut  from 
under  the  feet  of  spiritualism,  just  as  the  old  superstitions, 
which  attributed  thunder  and  lightning  to  Divine  anger, 
were  finally  demolished  by  Franklin's  kite.  If,  on  the 
other  hand,  the  arch-medium,  Mr.  Home,  is  proved  to  be 
a  common  conjuror,  then  surely  the  dupes  of  the  smaller 
"  mediumistic"  fry  will  have  their  eyes  opened,  provided 
the  cerebral  disturbance  which  spiritualism  so  often  in- 
duces has  not  gone  so  far  as  to  render  them  incurable  luna- 
tics. 

It  is  very  likely  that  I  shall  be  accused  of  gross  unchari- 
tablencss  in  thus  applying  the  term  lunatic  to  "  those  who 
differ  from  me,"  and  therefore  state  that  I  have  sad  and 
sufficient  reasons  for  doing  so. 

The  first  spiritualist  I  ever  knew,  and  with  whom  I  had. 


242  SCIENCE  IN  SHORT  CHAPTERS. 

many  conferences  on  the  subject  many  years  ago,  was  a  lady 
of  most  estimable  qualities,  great  intellectual  attainments, 
and  distinguished  literary  reputation.  I  watched  the  be- 
ginning and  the  gradual  progress  of  her  spiritual  "investi- 
gations," as  she  called  them,  and  witnessed  the  melancholy 
end — -shocking  delusions,  intellectual  shipwreck,  and  con- 
firmed, incurable  insanity,  directly  and  unmistakably  pro- 
duced by  the  action  of  these  hideous  superstitions  upon  an 
active,  excitable  imagination. 

I  well  remember  the  growing  symptoms  of  this  case, 
have  seen  their  characteristic  features  repeated  in  others, 
and  have  now  before  me  some  melancholy  cases  where  the 
same  changes,  the  same  decline  of  intellect  and  growth  of 
ravenous  credulity,  is  progressing  with  most  painfully  visi- 
ble distinctness. 

The  necessity  for  some  strong  remedy  is  the  more  urgent, 
inasmuch  as  the  diabolical  machinery  of  the  spiritual  im- 
postors has  been  so  much  improved  of  late.  The  lady 
whose  case  I  first  referred  to  had  reached  the  highest  ?rage 
of  spiritualistic  development — viz.,  the  lunatic  asylum — 
before  "  dark  seances"  had  been  invented,  or,  at  any  rate, 
before  they  were  introduced  into  this  country.  When  the 
conditions  of  these  seances  are  considered,  it  is  not  at  all 
surprising  that  persons  of  excitable  temperament,  espe- 
cially women,  should  be  morbidly  affected  by  them. 

We  are  endowed  with  certain  faculties,  and  placed  in  a 
world  wherein  we  may  exercise  them  healthfully  upon  their 
legitimate  objects.  Such  exercise,  properly  limited,  pro- 
motes the  growth  and  vigor  of  our  faculties;'  but  if  we  per- 
vert them  by  directing  them  to  illegitimate  objects,  we 
gradually  become  mad.  God  has  created  the  light,  and  fit- 
ted our  eyes  to  receive  it;  He  has  endowed  us  with  the 
sense  of  touch,  by  which  we  may  confirm  and  verify  the 
impressions  of  sight.  All  physical  phenomena  are  objects 
of  sense,  and  the  senses  of  sight  and  touch  are  the  masters 
of  all  the  other  senses. 

Can  anything,  then,  be  more  atrociously  perverse, 


more 


utterly  idiotic,  and  I  may  even  say  impious,  than  these 
dark  seance  investigations?  Is  it  possible  to  conceive  a 
more  melancholy  spectacle  of  intellectual  degradation  than 


SCIENCE  AM)  SPIRITUALISM.  243 

that  presented  by  a  group  of  human  victims  assembled  for 
the  purpose  of  "investigating  physical  manifestations," 
and  submitting,  as  a  primary  condition,  to  be  blinded  and 
handcuffed,  the  room  in  which  they  sit  being  made  quite 
dark,  and  both  hands  of  each  investigator  being  firmly 
held  by  those  of  his  neighbors.  That  is  to  say,  the  pri- 
mary conditions  of  making  these  physical  investigations  is 
that  each  investigator  shall  be  deprived  of  his  natural  facul- 
ties for  doing  so. 

When  we  couple  this  with  the  fact  that  these  meetings 
are  got  up — publicly  advertised  by  adventurers  who  make 
their  livelihood  by  the  fees  paid  by  their  hoodwinked  and 
handcuffed  customers— is  it  at  all  surprising  that  those 
who  submit  to  such  conditions  should  finish  their  re- 
searches in  a  lunatic  asylum? 

The  gloom,  the  mystery,  the  unearthly  objects  of  search, 
the  mysterious  noises,  and  other  phenomena  so  easily 
manipulated  in  the  presence  of  those  who  can  see  nothing 
and  feel  only  the  sympathetic  twitching  of  another  pair  of 
trembling  hands,  naturally  excites  very  powerfully  the  poor 
creatures  who  pay  their  half-crowns  and  half-guineas  with 
any  degree  of  faith;  and  this  unnatural  excitement,  if  fre- 
quently repeated,  goes  on  increasing  till  the  brain  becomes 
incurably  diseased. 

Present  space  will  not  permit  me  to  enter  upon  another 
branch  of  this  subject,  viz. :  the  moral  degradation  and  the 
perversion  of  natural,  unsophisticated,  and  wholesome  the- 
ology, which  these  spiritual  delusions  are  generating. 

I  am  no  advocate  for  rectifying  moral  and  intellectual 
evils  by  police  interference,  or  I  should  certainly  recommend 
the  bracing  air  of  Dartmoor  for  the  mediums  who  publicly 
proclaim  that  their  familiar  spirit  "  Katey  "  has  lately  trans- 
lated a  lady  through  a  space  of  three  miles,  and  through 
the  walls,  doors,  and  ceiling  of  the  house  in  which  a  dark 
seance  was  being  held,  and  placed  her  upon  the  table  in 
the  midst  of  the  circle  so  rapidly  that  the  word  "onions" 
she  had  just  written  in  her  domestic  inventory  was  not  yet 
dried  when  the  lights  were  brought  and  she  was  found 
there. 

This  "  lady,"  which  her  name  is  Guppy,  is,  of  course, 


244  SCIENCE  IN  SHORT  CHAPTERS. 

another  professional  medium,  and  yet  there  are  people  in 
London  who  gravely  believe  this  story,  and  also  the  appen- 
dix, viz. :  that  another  member  of  the  mediumistic  firm, 
finding  that  Mrs.  G.  was  very  incompletely  dressed,  and 
much  abashed  thereby,  was  translated  by  the  same  spirit, 
Katey,  to  her  house  and  back  again  through  the  door-panel 
to  fetch  proper  garments.  If  I  could  justify  the  appre- 
hension and  imprisonment  of  poor  gipsy  fortune-tellers, 
I  certainly  should  advocate  the  close  confinement  of  Mrs. 
Guppy  and  her  male  associates,  and  thus  afford  the  potent 
spirit,  Katey,  an  opportunity  of  further  manifestation  by 
translating  them  through  the  prison  walls  and  back  to 
Lamb's  Conduit  Street. 

( The  above  letter  appeared  in  the  "  Birmingham  Morn- 
ing News"  of  July  18,  1871 ;  the  following  on  November 
15.  It  refers  to  an  article  in  the  "  Quarterly  \Eeview"  of 
October,  1871.)- 

The  interest  excited  by  Mr.  Crookes's  investigations  on 
Psychic  Force  is  increasing;  the  demand  for  the  "  Quartely 
Keview"  and  the  "Quarterly  Journal  of  Science"  is  so 
great  that  Mudie  and  other  proprietors  of  lending  libraries 
have  largely  increased  their  customary  supplies,  and  are  still 
besieged  with  further  excess  of  demand.  Not  only  bor- 
rowers, but  purchasers  also  are  supplied  with  difficulty.  I 
yesterday  received  a  post-card  from  a  bookseller,  inscribed 
as  follows  :  "Cannot  get  a  '  Quarterly  Keview '  in  the  City, 
so  shall  be  unable  to  send  it  to  you  until  to-morrow."  I 
have  waited  three  days,  and  am  now  obliged  to  go  to  the 
reading-room  to  make  my  quotations. 

There  is  good  and  sufficient  reason  for  this,  indepen- 
dently of  the  absence  of  Parliamentary  and  war  news,  and 
the  dearth  of  political  revolutions.  Either  a  new  and  most 
extraordinary  natural  force  has  been  discovered,  or  some 
very  eminent  men  specially  trained  in  rigid  physical  in- 
vestigation have  been  the  victims  of  a  marvelous,  unpre- 
cedented, and  inexplicable  physical  delusion.  I  say  un- 
precedented, because,  although  we  have  records  of  many 
popular  delusions  of  similar  kind  and  equal  magnitude* 
and  speculative  delusions  among  the  learned,  I  can  cite  no 
instance  of  skillful  experimental  experts  being  utterly  and 


SCIENCE  AND  SPIRITUALISM.  245 

repeatedly  deceived  by  the  mechanical  action  of  experi- 
mental test  apparatus  carefully  constructed  and  used  by 
themselves. 

As  the  interest  in  the  subject  is  rapidly  growing,  my 
readers  will  probably  welcome  a  somewhat  longer  gossip 
on  this  than  I  usually  devote  to  a  single  subject. 

Such  an  extension  is  the  more  demanded  as  the  news- 
paper and  magazine  articles  which  have  hitherto  ap- 
peared have,  for.  the  most  part,  by  following  the  lead  of 
the  "  Quarterly  Review,"  strangely  muddled  the  whole 
subject,  and  misstated  the  position  of  Mr.  Crookes  and 
others.  In  the  first  place,  all  the  writers  who  follow  the 
"  Quarterly  "  omit  any  mention  or  allusion  to  Mr.  Crookes's 
preliminary  paper  published  in  July,  1870,  which  has  a 
most  important  bearing  on  the  whole  subject,  as  it  ex- 
pounds the  object  of  all  the  subsequent  researches. 

Mr.  Crookes  there  states  that  "  Some  weeks  ago  the  fact 
that  I  was  engaged  in  investigating  Spiritualism,  so-called, 
was  announced  in  a  contemporary  (the  "  Athenasum"),  and 
in  consequence  of  the  many  communications  I  have  since 
received,  I  think  it  desirable  to  say  a  little  concerning  the 
investigations  which  I  have  commenced.  Views  or  opinions 
I  cannot  be  said  to  possess  on  a  subject  which  I  do  not  pro- 
fess to  understand.  I  consider  it  the  duty  of  scientific  men, 
who  have  learned  exact  modes  of  working,  to  examine  phe- 
nomena which  attract  the  attention  of  the  public,  in  order 
to  confirm  their  genuineness,  or  to  explain,  if  possible,  the 
delusions  of  the  honest,  and  to  expose  the  tricks  of  the  de- 
ceivers/'' 

He  then  proceeds  to  state  the  case  of  Science  versus  Spir- 
itualism thus  : — "  The  Spiritualist  tells  of  bodies  weighing 
50  or  100  Ibs.  being  lifted  up  into  the  air  without  the  in- 
tervention of  any  known  force ;  but  the  scientific  chemist 
is  accustomed  to  use  a  balance  which  will  render  sensible  a 
weight  so  small  that  it  would  take  ten  thousand  of  them  to 
weigh  one  grain  ;  he  is,  therefore,  justified  in  asking  that  a 
power,  professing  to  be  guided  by  intelligence,  which  will 
toss  a  heavy  body  to  the  ceiling,  shall  also  cause  his  deli- 
cately-poised balance  to  move  under  test  conditions."  "  The 
Spiritualist  tells  of  rooms  and  houses  being  shaken,  even  to 


246  SCIENCE  IN  SHORT  CHAPTERS. 

injury,  by  superhuman  power.  The  man  of  science  merely 
asks  for  a  pendulum  to  be  sent  vibrating  when  it  is  in  a  glass- 
case,  and  supported  on  solid  masonary."  "  The  Spiritualist, 
tells  of  heavy  articles  of  furniture  moving  from  one  room  to 
another  without  human  agency.  But  the  man  of  science 
has  made  instruments  which  will  divide  an  inch  into  a  mil- 
lion parts,  and  he  is  justified  in  doubting  the  accuracy  of 
the  former  observations,  if  the  same  force  is  powerless  to 
move  the  index  of  his  instrument  one  poor. degree."  "  The 
Spiritualist  tells  of  flowers  with  the  fresh  dew  on  them,  of 
fruit,  and  living  objects  being  carried  through  closed  win- 
dows, and  even  solid  brick  walls.  The  scientific  investiga- 
tor naturally  asks  that  an  additional  weight  (if  it  be  only 
the  1000th  part  of  a  grain)  be  deposited  on  one  pan  of  his 
balance  when  the  case  is  locked.  And  the  chemist  asks  for 
the  1000th  part  of  a  grain  of  arsenic  to  be  carried  through 
the  sides  of  a  gas  tube  in  which  pure  water  is  hermetically 


These  and  other  requirements  are  stated  by  Mr.  Crookes, 
together  with  further  exposition  of  the  principles  of  strict 
inductive  investigation,  as  it  should  be  applied  to  such  an 
inquiry.  A  year  after  this  he  published  an  account  of  the 
experiments,  which  I  described  in  a  former  letter,  and 
added  to  his  own  testimony  that  of  the  eminent  physicist 
and  astronomer,  Dr.  Huggins  and  Serjeant  Cox.  Subse- 
quently, that  is,  in  the  last  number  of  the  "  Quarterly  Jour- 
nal of  Science,"  he  has  published  the  particulars  of  another 
series  of  experiments. 

I  will  not  now  enter  upon  the  details  of  these,  but  merely 
state  that  the  conclusions  of  Mr.  Crookes  are  directly  op- 
posed to  those  of  the  Spiritualists.  He  positively,  distinctly, 
and  repeatedly  repudiates  all  belief  in  the  operations  of  the 
supposed  spirits,  or  of  any  other  supernatural  agency  what- 
ever, and  attributes  the  phenomena  he  witnessed  to  an  en- 
tirely different  organ,  viz.:  to  the  direct  agency  of  the  me- 
dium. He  supposes  that  a  force  analogous  to  that  which 
the  nerves  convey  from  their  ganglionic  centres  to  the 
muscles,  in  producing  muscular  contraction,  may  by  an 
effort  of  the  will  be  transmitted  to  external  inanimate 
matter,  in  such  a  manner  as  to  influence,  in  some  degree, 


SCIENCE  AND  SPIRITUALISM.  247 

its  gravitating  power,  and  produce  vibratory  motion.  He 
calls  this  the  psychic  force. 

Now,  this  is  direct  and  unequivocal  emh'-spiritualisrn.  It 
is  a  theory  set  up  in  opposition  to  the  supernatural  hypo- 
theses of  the  Spiritualists,  and  Mr.  Crookes's  position  in 
reference  to  Spiritualism  is  precisely  analogous  to  that 
of  Faraday  in  reference  to  table-turning.  For  the  same 
reasons  as  those  above-quoted,  the  great  master  of  experi- 
mental investigation  examined  the  phenomena  called  table- 
turningj  and  he  concluded  that  they  were  due  to  muscular 
force,  just  as  Mr.  Crookes  concludes  that  the  more  com- 
plex phenomena  he  has  examined  are  due  to  psychic  force. 

Speaking  of  the  theories  of  the  Spiritualists,  Mr.  Crookes, 
in  his  first  paper  (July,  1870),  says:  "  The  pseudo-scientific 
Spiritualist  professes  to  know  every  thing.  Xo  calculations 
trouble  his  serenity;  no  hard  experiments,  no  laborious 
readings;  no  weary  attempts  to  make  clear  in  words  that 
which  has  rejoiced  the  heart  and  elevated  the  mind.  He 
talks  glibly  of  all  sciences  and  arts,  overwhelming  the  in- 
quirer with  terms  like  '  electro-biologise,'  'psychologise,' 
'animal  magnetism,' etc.,  a  mere  play  upon  words,  show- 
ing ignorance  rather  than  understanding."  And  further 
on  he  says:  "  I  confess  that  the  reasoning  of  some  Spiritu- 
alists would  almost  seem  to  justify  Faraday's  severe  state- 
ment— that  many  dogs  have  the  power  of  coming  to  more 
logical  conclusions." 

I  have  already  referred  to  the  muddled  misstatement  of 
Mr.  Crookes's  position  by  the  newspaper  writers,  who  al- 
most unanimously  describe  him  and  Dr.  Huggins  as  two 
distinguished  scientific  men  who  have  recently  been  con- 
verted to  Spiritualism.  The  above  quotations,  to  which, 
if  space  permitted,  I  might  add  a  dozen  others  from  either 
the  first,  the  second,  or  the  third  of  Mr.  Crookes's  papers, 
in  which  he  as  positively  and  decidedly  controverts  the 
dreams  of  the  Spiritualists,  will  show  how  egregiously  these 
writers  have  been  deceived.  They  have  relied  very  natu- 
rally on  the  established  respectability  of  the  "  Quarterly  Ke- 
view,"  and  have  thus  deluded  both  themselves  and  their 
readers.  Considering  the  marvelous  range  of  subjects 
these  writers  have  to  -treat,  and  the  acres  of  paper  they 


248  SCIENCE  IN  SHORT  CHAPTERS. 

daily  cover,  it  is  not  surprising  that  they  should  have  been 
thus  misled  in  reference  to  a  subject  carrying  them  consid- 
erably out  of  their  usual  track;  but  the  offence  of  the  "  Quar- 
terly" is  not  so  venial.  It  assumes,  in  fact,  a  very  serious 
complexion  Avhen  further  investigated. 

The  title  of  the  article  is  "  Spiritualism  and  its  Recent 
Converts,"  and  the  "recent  converts"  most  specially  and 
prominently  named  are  Mr.  Crookes  and  Dr.  Hugging. 
Serjeant  Cox  is  also  named,  but  not  as  a  recent  convert; 
for  the  reviewer  describes  him  as  an  old  and  hopelessly  in- 
fatuated Spiritualist.  Knowing  nothing  of  Serjeant  Cox, 
I  am  unable  to  say  whether  the  reviewer's  very  strong  per- 
sonal statements  respecting  him  are  true  or  false — whether 
he  really  is  "one  of  the  most  gullible  of  the  gullible, "etc., 
though  I  must  protest  against  the  bad  taste  which  is  dis- 
played in  the  attack  which  is  made  upon  this  gentleman. 
The  head  and  front  of  his  offending  consists  in  having 
certified  to  the  accuracy  of  certain  experiments;  and  for 
having  simply  done  this,  the  reviewer  proceeds,  in  accord- 
ance with  the  lowest  tactics  of  Old  Bailey  advocacy,  to  bully 
the  witness,  and  to  publish  disparaging  personal  details  of 
what  he  did  twenty-five  years  ago. 

Dr.  Huggins,  who  has  had  nothing  further  to  do  with 
the  subject  than  simply  to  state  that  he  witnessed  what  Mr. 
Crookes  described,  and  who  has  not  ventured  upon  one 
word  of  explanation  of  the  phenomena,  is  similarly  treated. 

The  reviewer  goes  out  of  his  way  to  inform  the  public 
that  Dr.  Huggins  is,  after  all,  only  a  brewer,  by  artfully 
stating  that,  "like  Mr.  Whitbread,  Mr.  Lassell,  and  other 
brewers  we  could  name,  Dr.  Huggins  attached  himself  in 
the  first  place  to  the  study  of  astronomy. "  He  then  pro- 
ceeds to  sneer  at  "such  scientific  amateurs,"  by  informing 
the  public  that  they  "labor,  as  a  rule,  under  a  grave  dis- 
advantage, in  the  want  of  that  broad  basis  of  scientific  cul- 
ture which  alone  can  keep  them  from  the  narrowing  and 
pervertive  influence  of  a  limited  specialism." 

The  reviewer  proceeds  to  say  that  he  has  "no  reason  to 
believe  that  Dr.  Huggins  constitutes  an  exception"  to  this 
rule,  and  further  asserts  that  he  is  justified  in  concluding 
that  Dr.  Huggins  is  ignorant  of  "every  other  department 


SCIENCE  AND  SPIRITUALISM.  249 

• 

of  science  than  the  small  subdivision  of  a  branch  to  which 
he  has  so  meritoriously  devoted  himself."  Mark  the 
words,  "small  subdivision  of  a  branch."  Merely  a  twig  of 
the  tree  of  science  is,  according  to  this  most  unveracious 
writer,  all  that  Dr.  Huggins  has  ever  studied. 

If  a  personal  vindication  were  the  business  of  this  letter 
I  could  easily  show  that  these  statements  respecting  the 
avocations,  the  scientific  training,  and  actual  attainments 
of  Dr.  Huggins  are  gross  and  atrocious  misrepresentations; 
but  Dr.  Huggins  has  no  need  of  my  championship;  his 
high  scientific  position,  the  breadth  and  depth  of  his  gen- 
eral attainments,  and  the  fact  that  he  is  not  Huggins  the 
brewer,  are  sufficiently  known  to  all  in  the  scientific  world, 
with  the  exception  of  the  "  Quarterly"  reviewer. 

My  object  is  not  to  discuss  the  personal  question  whether 
book-making  and  dredging  afford  better  or  worse  training 
for  experimental  inquiry  than  the  marvelously  exact  and 
exquisitely  delicate  manipulations  of  the  modern  observa- 
tory and  laboratory,  but  to  protest  against  this  attempt  to 
stop  the  progress  of  investigation,  to  damage  the  true  in- 
terests of  science  and  the  cause  of  truth,  by  throwing  low 
libellous  mud  upon  any  and  everybody  who  steps  at  all 
aside  from  the  beaten  paths  of  ordinary  investigation. 

The  true  business  of  science  is  the  discovery  of  truth;  to 
seek  it  wherever  it  may  be  found,  to  pursue  it  through  bye- 
ways  as  well  as  highways,  and,  having  found  it,  to  proclaim 
it  plainly  and  fearlessly,  without  regard  to  authority,  fash- 
ion, or  prejudice.  If,  however,  such  influential  magazines  as 
the"  Quarterly  Review"  are  to  be  converted  into  the  vehicles 
of  artful  and  elaborate  efforts  to  undermine  the  scientific 
reputation  of  any  man  who  thus  does  his  scientific  duty,  the 
time  for  plain  speaking  and  vigorous  protest  has  arrived. 

My  readers  will  be  glad  to  learn  that  this  is  the  general 
feeling  of  the  leading  scientific  men  of  the  metropolis; 
whatever  they  may  think  of  the  particular  investigations 
of  Mr.  Crookes,  they  are  unanimous  in  expressing  their  de- 
nunciations of  this  article. 

The  attack  upon  Mr.  Crookes  is  still  more  malignant  than 
that  upon  Dr.  Huggins.  Speaking  of  Mr.  Crookes's  fel- 
lowship of  the  Royal  Society,  the  reviewer  says:  "  We  speak 


250  SCIENCE  IN  SHORT  CHAPTERS. 

advisedly  when  we  say  that  this  distinction  was  conferred  on 
him  with  considerable  hesitation;"  and  further  that  "Wo 
are  assured,  on  the  highest  authority,  that  he  is  regarded 
among  chemists  as  a  specialist  of  specialists,  being  totally 
destitute  of  any  knoivledge  of  chemical  philosophy,  and  ut- 
terly untrustworthy  as  to  any  inquiry  which  requires  more 
than  technical  knowledge  for  its  successful  conduct." 

The  italics  in  these  quotations  are  my  own,  placed  there 
to  mark  certain  statements  to  which  no  milder  term  than 
that  of  falsehood  is  applicable.  The  history  of  Mr.  Crookes's 
admission  to  the  Eoyal  Society  will  shortly  be  published, 
when  the  impudence  of  the  above  statement  respecting  it 
will  be  unmasked;  and  the  other  quotations  I  have  em- 
phasized are  sufficiently  and  abundantly  refuted  by  Mr. 
Crookes's  published  works,  and  his  long  and  able  conduct 
of  the  Chemical  News,  which  is  the  only  and  the  recognized 
British  periodical  representative  of  chemical  science. 

If  space  permitted,  I  could  go  on  quoting  a  long  series 
of  misstatements  of  matters  of  fact  from  this  singularly  un- 
veracious  essay.  The  writer  seems  conscious  of  its  general 
character,  for,  in  the  midst  of  one  of  his  narratives,  he  breaks 
out  into  a  foot-note,  stating  that  "  This  is  not  an  invention 
of  our  own,  but  a  fact  communicated  to  us  by  a  highly  in- 
telligent witness,  who  was  admitted  to  one  of  Mr.  Orookes's 
seances."  I  have  taken  the  liberty  to  emphasize  the  proper 
word  in  this  very  explanatory  note. 

The  full  measure  of  the  injustice  of  prominently  thrust- 
ing forward  Dr.  Huggius  and  Mr.  Crookes  as  "recent  con- 
verts" to  Spiritualism  will  be  seen  by  comparing  the  re- 
viewer's own  definition  of  Spiritualism  with  Mr.  Crookes's 
remarks  above  quoted.  The  reviewer  says  that  "  The  funda- 
mental tenet  of  the  Spiritualist  is  the  old  doctrine  of  com- 
munication between  the  spirits  of  the  departed  and  souls  of 
the  living." 

-  This  is  the  definition  of  the  reviewer,  and  his  logical  con- 
clusion is  that  Mr.  Crookes  is  a  Spiritualist  because  he  ex- 
plicitly denies  the  fundamental  tenet  of  Spiritualism,  and 
Dr.  Huggins  is  a  Spiritualist  because  he  says  nothing  what- 
ever about  it. 

If  examining  the  phenomena  upon  which  the  Spiritualist 


MATHEMATICAL   FICTIONS.  251 

builds  his  "fundamental  tenet,"  and  explaining  them  in 
some  other  manner,  constitutes  conversion  to  Spiritualism, 
then  the  reviewer  is  a  far  more  thoroughgoing  convert 
than  Mr.  Crookes,  who  only  attempts  to  explain  the  mild 
phenomena  of  his  own  experiments,  while  the  reviewer 
goes  in  for  everything,  including  even  the  apotheosis  of 
Mrs.  Guppy  and  her  translation  through  the  ceiling,  a 
story  which  is  laughed  at  by  Mr.  Crookes  and  everybody 
else,  excepting  a  few  of  the  utterly  crazed  disciples  of  the 
"  Lamb's  Conduit  Mediums"  and  the  "  Quarterly"  review- 
er, who  actually  attempts  to  explain  it  by  his  infallible  and 
ever  applicable  physiological  nostrum  of  "unconscious  cere- 
bration." 

No  marvelous  story  either  of  ancient  or  modern  date  is 
too  strong  for  this  universal  solvent,  which  according  to 
the  reviewer,  is  the  sole  and  glorious  invention  of  Dr.  Car- 
penter. Space  will  not  now  permit  me  to  further  describe 
"unconscious  cerebration"  and  its  vast  achievements,  but 
I  hope  to  find  a  corner  for  it  hereafter. 

I  may  add  that  the  name  of  the  reviewer  is  kept  a  pro- 
found secret,  and  yet  is  perfectly  well-known,  as  everybody 
who  reads  the  article  finds  it  out  when  he  reaches  those 
parts  which  describe  Dr.  Carpenter's  important  physio- 
logical researches  and  discoveries. 


MATHEMATICAL  FICTIONS. 
(BRITISH  ASSOCIATION,  1871.) 

THE  President's  inaugural  address,  which  was  going 
through  the  press  in  London  while  being  spoken  in  Edin- 
burgh, has  already  been  subject  to  an  unusual  amount  of 
sharp  criticism.  For  my  own  part  I  cannot  help  regarding 
it  as  one  of  the  least  satisfactory  pf  all  the  inaugural  ad- 
dresses that  have  yet  been  delivered  at  these  annual  meet- 
ings. They  have  been  of  two  types,  the  historical  and  the 
controversial;  the  former  prevailing.  In  the  historical  ad- 


252  SCIENCE  IN  SHORT  CHAPTERS. 

dresses  the  President  lias  usually  made  a  comprehensive 
and  instructive  survey  of  the  progress  of  the  whole  range 
of  science  during  the  past  year,  and  has  dwelt  more  partic- 
ularly on  some  branch  which  from  its  own  intrinsic  merits 
has  claimed  special  attention,  or  which  his  own  special 
attainments  have  enabled  him  to  treat  with  the  greatest 
ability  and  authority.  A  few  President's  have,  like  Dr. 
Huxley  last  year,  taken  up  a  particular  subject  only,  and 
have  discussed  it  more  thoroughly  than  they  could  have 
done  had  they  also  attempted  a  general  historical  survey. 

Every  President  until  1871  has  scrupulously  kept  in  .view 
his  judicial  position,  and  the  fact  that  he  'is  addressing,  not 
merely  a  few  learned  men,  but  the  whole  of  England,  if  not 
the  whole  civilized  world.  They  have  therefore  clearly 
distinguished  between  the  established  and  the  debatable 
conclusions  of  science,  between  ascertained  facts  and  mere 
hypotheses,  have  kept  this  distinction  so  plainly  before  their 
auditors  that  even  the  most  uninitiated,  could  scarcely  con- 
found the  one  with  the  other. 

In  Sir  William  Thomson's  address  this  desirable  rule  is 
recklessly  violated.  He  tells 'his  unsophisticated  audience 
that  Joule  was  able  "  to  estimate  the  average  velocity  of  the 
ultimate  molecules  or  atoms"  of  gases,  and  thus  determined 
the  atomic  velocity  of  hydrogen  "at  6225  feet  per  second 
at  temperature  60  degs.  Fahr.,  and  6055  feet  at  the  freezing 
point;"  that  "  Clausius  took  fully  into  account  the  impacts 
of  molecules  upon  one  another,  and  the  kinetic  energy  of 
relative  motion  of  the  matter  constituting  an  individual 
atom;"  and  that  "  he  investigated  the  relation  between  their 
diameters,  the  number  in  a  given  space,  and  the  mean 
length  of  path  from  impact  to  impact,  and  so  gave  the 
foundation  for  estimates  of  the  absolute  dimensions  of 
atoms."  Also  that  "Loschmidt,  in  Vienna,  had  shown, 
and  not  much  later  Stoney,  independently,  in  England, 
showed  how  to  reduce  from  Clausius  and  Maxwell's  kinetic 
theory  of  gases  a  superior  limit  to  the  number  of  atoms  in  a 
given  measurable  space." 

The  confiding  auditor  follows  the  President  through 
further  disquisitions  on  the  "  superlatively  grand  question, 
what  is  the  inner  mechanism  of  an  atom?"  and  a  minute 


MATHEMATICAL  FICTIONS.  253 

and  most  definite  description  of  the  "regular  elastic  vibra- 
tions" of  "  the  ultimate  atom  of  sodium,"  of  the  manner  in 
which  "any  atom  of  gas,  when  struck  and  left  to  itself, 
vibrates  with  perfect  purity  its  fundamental  note  or  notes," 
and  how,  "in  a  highly  attenuated  gas,  each  atom  is  very 
rarely  in  collision  with  other  atoms,  and  therefore  is  nearly 
at  all  times  in  a  state  of  true  vibration,"  while  "  in  denser 
gases  each  atom  is  frequently  in  collision;"  besides,  a  great 
deal  more,  in  all  of  which  the  existence  of  these  atoms  is 
coolly  taken  for  granted,  and  treated  as  a  fundamental 
established  scientific  fact. 

After  hearing  all  these  oracular  utterances  concerning 
atoms,  the  unsophisticated  listener  before  mentioned  will 
be  surprised  to  learn  that  no  human  being  has  ever  seen  an 
atom  of  any  substance  whatever;  that  there  exists  absolutely 
no  direct  evidence  of  the  existence  of  any  such  atoms;  that 
all  these  atoms  oi  which  Sir  W.«  Thomson  speaks  so  confi- 
dently and  familiarly,  and  dogmatically,  are  pure  fragments 
of  the  imagination. 

He  will  be  still  further  surprised  to  learn  that  the  bare 
belief  in  the  existence  of  ultimate  atoms  as  a  merely  hypo- 
thetical probability  is  rejected  by  many  of  the  most  emi- 
nent of  scientific  men,  and  that  among  those  who  have 
disputed  the  idea  of  the  atomic  constitution  of  matter,  is 
the  great  Faraday  himself;  that  the  question  of  the  exist- 
ence or  non-existence  of  atoms  has  recently  been  rather 
keenly  discussed;  and  that  even  on  the  question  of  the  per- 
missibility of  admitting  their  hypothetical  existence,  scien- 
tific opinion  is  divided;  and  that  such  a  confident  assump- 
tion of  their  existence  as  forms  the  basis  of  this  part  of  the 
President's  address  is  limited  to  only  a  small  section  of 
mutually  admiring  transcendental  mathematicians,  Sir  W. 
Thomson  being  the  most  admired  among  them,  as  shown 
by  the  address  of  Professor  Tait  to  Section  A. 

It  would  have  been  perfectly  legitimate  and  most  desir- 
able that  Sir  W.  Thomson  should  give  the  fullest  and  most 
favorable  possible  statement  of  the  particular  hypotheses 
upon  which  he  and  his  friends  have  exercised  their  unques- 
tionably great  mathematical  skill;  but  he  should  have 
stated  them  as  what  they  are,  and  for  what  they  are  worth. 


254  SCIENCE  IN  SHORT  CHAPTERS. 

and  have  clearly  distinguished  between  such  hypotheses 
and  the  established  facts  of  universally  admitted  science. 
Instead  of  doing  this,  he  has  so  mixed  up  the  actual  dis- 
coveries of  indisputable  facts  with  these  mere  mathematical 
fancies  as  to  give  them  both  the  semblance  of  equally  au- 
thoritative scientific  acceptance,  and  thus,  without  any 
intention  to  deceive  anybody,  must  have  misled  nearly  all 
the  outside  public  who  have  heard  or  read  his  address. 

As  these  letters  are  mainly  intended  for  those  who  are 
too  much  engaged  in  other  pursuits  to  study  science  syste- 
matically, and  as  most  of  the  readers  of  such  letters  will,  as 
a  matter  of  course,  read  the  inaugural  address  of  the  Presi- 
dent of  the  British  Association,  I  have  accepted  the  duty 
of  correcting  among  my  own  readers  the  false  impression 
which  this  address  may  create. 

As  a  set-off  to  the  authoritative  utterances  of  Sir  "W. 
Thomson  on  the  subject  pf  atoms,  I  quote  the  following 
from  an  Italian  philosopher,  who,  during  the  present  year, 
is  holding  in  Italy  a  position  very  similar  to  that  of  the 
annual  President  of  our  British  Association. 

Professor  Cannizzaro  has  been  elected  by  a  society  of 
Italian  chemists  to  act  as  this  year's  director  of  a  Chronicle 
of  the  Progress  of  Chemical*  Science  in  Italy  and  abroad. 
In  this  capacity  he  has  published  an  inaugural  treatise  on 
the  history  of  modern  chemical  theory,  in  the  course  of 
which  he  thus  speaks  of  the  over-confident  atomic  theorists: 
"  They  often  speak  on  molecular  subjects  with  as  much 
dogmatic  assurance  as  though  they  had  actually  realized 
the  ingenious  fiction  of  Laplace — had  constructed  a  micro- 
scope by  which  they  could  detect  the  molecules,  and  observe 
the  number,  forms,  and  arrangements  of  their  constituent 
atoms,  and  even  determine  the  direction  and  intensity  of 
their  mutual  actions.  Many  of  these  things,  offered  at 
what  they  are  worth — that  is,  as  hypotheses  more  or  less 
probable,  or  as  simple  artifices  of  the  intellect — may  serve, 
and  really  have  served,  to  collocate  facts  and  incite  to 
further  investigations  which,  one  day  or  other,  may  lead 
to  a  true  chemical  theory;  but,  when  perverted  by  being 
stated  as  truths  already  demonstrated,  they  falsify  the  in- 
tellectual education  of  the  students  of  inductive  science, 


MATHEMATICAL  FICTIONS.  255 

and  bring  reproach  on  the  modern  progress  of  chemis- 
try.'* 

"l  translate  the  above  from  the  first  page  of  the  first 
number  of  the  "Gazetta  Ohimica  Italiana,"  published  at 
Palermo  in  January  last.  Had  these  words  been  written 
in  Edinburgh  on  the  evening  of  the  2d  of  August,  in 
direct  application  to  Sir  William  Thomson's  address,  they 
could  not  have  described  more  pointedly  and  truly  the  pre- 
vailing vice  of  this  production.  If  space  permitted,  I 
could  go  further  back  and  quote  the  words  of  Lord  Bacon, 
from  the  great  text-book  of  inductive  philosophy,  wherein 
he  denounces  the  worship  of  all  such  intellectual  idols  as 
our  modern  mathematical  dreamers  have  created,  and 
which  they  so  fervently  adore. 

An  able  writer  in  the  Daily  News  of  last  Friday  is 
very  severe  upon  the  biological  portion  of  the  President's 
address,  which  contains  a  really  original  hypothesis.  Sir 
W.  Thomson  having  stated  that  he  is  "  ready  to  adopt  as 
an  article  of  scientific  faith,  true  through  all  space  and 
through  all  time,  that  life  proceeds  from  life,  and  from 
nothing  but  life,"  asks  the  question,  "How  then  did  life 
originate  on  the  earth?"  and  tells  us  that  "if  a  probable 
solution  consistent  with  the  ordinary  course  of  nature  can 
be  found,  we  must  not  invoke  an  abnormal  act  of  creative 
power." 

He  assumes,  with  that  perfect  confidence  in  mathe- 
matical hypotheses  which  is  characteristic  of  the  school  of 
theorists  which  he  leads,  that  "tracing  the  physical  history 
of  the  earth  backwards,  on  strictly  dynamical  principles, 
we  are  brought  to  a  red-hot  melted  globe,  on  which  no  life 
could  exist;"  and  then,  to  account  for  the  beginning  of 
life  on  our  earth  as  it  cooled  down,  he  creates  another 
imaginary  world,  which  he  brings  in  collision  with  a  second 
similar  creation,  and  thereby  shatters  it  to  fragments.  He 
further  imagines  that  one  of  these  imaginary  broken-up 
worlds  was  already  stocked  with  the  sort  of  life  which  he 
says  can  only  proceed  from  life,  and  that  from  such  a  world 
thus  stocked  and  thus  smashed  "many  great  and  small 
fragments  carrying  seed  and  living  plants  and  animals 
would  undoubtedly  be  scattered  through  space;"  and  that, 


256  SCIENCE  IN  SHORT  CHAPTERS. 

"  if  at  the  present  instant  no  such  life  existed  upon  this 
earth,  one  such  stone  falling  upon  it  might,  by  what  we 
blindly  call  natural  causes,  lead  to  its  becoming  covered 
with  vegetation." 

The  conclusion  of  this  paragraph  is  instructively  charac- 
teristic of  the  philosophy  of  Sir  William  Thomson  and  his 
admirers.  He  says  that  "  the  hypothesis  that  life  origi- 
nated on  this  earth  through  moss-grown  fragments  of  another 
world  may  seem  wild  and  visionary  ;  all  I  maintain  is  that 
it  is  not  unscientific" 

I  have  italicized  the  phrases  which,  put  together,  express 
the  philosophy  of  this  school  of  modern  manufacturers  of 
mathematical  hypotheses.  It  matters  not  to  them  how 
"  wild  and  visionary,"  how  utterly  gratuitous  any  assump- 
tion may  be,  it  is  not  unscientific  provided  it  can  be  in- 
vested in  formulae,  and  worked  out  mathematically.  These 
transcendental  mathematicians  are  struggling  to  carry  phi- 
losophy back  to  the  era  of  Duns  Scotus,  when  the  greatest 
triumph  of  learning  was  to  sophisticate  so  profoundly  an 
obvious  absurdity  that  no  ordinary  intellect  could  refute  it. 

Fortunately  for  the  progress  of  humanity,  there  are  other 
learned  men  who  firmly  maintain  that  the  business  of 
science  is  the  discovery  and  teaching  of  simple  sober  truth. 

The  writer  of  the  Daily  News  article  above  referred 
to  very  charitably  suggests  that  Sir  W.  Thomson  may  be 
"poking  fun  at  some  of  his  colleagues,"  and  compares  the 
moss-grown  meteorite  hypothesis  with  the  Hindoo  parable 
which  explains  the  stability  of  the  earth  by  stating  that  it 
stands  on  the  back  of  a  monster  tortoise,  that  the  tortoise 
rests  upon  the  back  of  a  gigantic  elephant,  which  stands 
upon  the  shell  of  a  still  bigger  tortoise,  resting  on  the  back 
of  another  still  more  gigantic  elephant,  and  so  on.  Sir  "W. 
Thomson,  of  course,  requires  to  smash  two  more  worlds  in 
order  to  provide  a  moss-grown  fragment  for  starting  thv 
life  upon  the  world  which  was  broken  up  for  our  benefit, 
and  so  on  backwards  ad  infinitum. 


WORLD-SMASHING.  257 


WORLD-SMASHING. 

SIB  W.  THOMSON'S  moss-grown  fragment  of  a  shattered 
world  is  not  yet  forgotten.  In  the  current  number  of  the 
Cornhill  Magazine  (January,  1872)  it  is  very  severely 
handled;  the  more  severely,  because  the  writer,  though 
treating  the  subject  quite  popularly,  sljpws  the  fallacy  of 
the  hypothesis,  even  when  regarded  from  the  point  of  view 
of  Sir  W.  Thomson's  own  special  department  of  study. 
That  an  eminent  mathematician  should  make  a  great  slip 
when  he  ventures  upon  geological  or  physiological  ground 
is  not  at  all  surprising  ;  it  is,  in  fact,  quite  to  be  expected, 
as  there  can  be  no  doubt  that  the  close  study  of  pure 
mathematics,  by  directing  the  mind  to  processes  of  calcula- 
tion rather  than  to  phenomena,  induces  that  sublime 
indifference  to  facts  which  has  characterized  the  purely 
mathematical  intellect  of  all  ages. 

It  is  not  surprising  that  a  philosopher  who  has  been 
engaged  in  measuring  the  imaginary  diameter,  describing 
the  imaginary  oscillations  and  gyrations  of  imaginary 
atoms,  and  the  still  more  complex  imaginary  behavior  of 
the  imaginary  constituents  of  the  imaginary  atmospheres 
by  which  the  mathematical  imagination  has  surrounded 
these  imaginary  atoms,  should  overlook  tire  vulgar  fact 
that  neither  mosses  nor  other  vegetables,  nor  even  their 
seeds,  can  possibly  retain  their  vitality  when  alternately 
exposed  to  the  temperature  of  a  blast  furnace,  and  that  of 
two  or  three  hundred  degrees  below  the  freezing  point; 
but  it  is  rather  surprising  that  the  purely  mathematical 
basis  of  this  very  original  hypothesis  of  so  great  a  mathe- 
matician should  be  mathematically  fallacious — in  plain 
language,  a  mathematical  blunder. 

In  order  to  supply  the  seed-bearing  meteoric  fragment 
by  which  each  planet  is  to  be  stocked  with  life,  it  is  neces- 
sary, according  to  Sir  W.  Thomson,  that  two  worlds — one 
at  least  nourishing  with  life — shall  be  smashed;  and,  in 
order  to  get  them  smashed  with  a  sufficient  amount  of  fre- 
quency to  supply  the  materials  for  his  hypothesis,  the 
learned  President  of  the  British  Association  has,  in  accord- 


258  SCIENCE  IN  8HOKT  CHAPTERS. 

ance  with  the  customary  ingenuity  of  mathematical  theo- 
rists, worked  out  the  necessary  mathematical  conditions, 
and  states  with  unhesitating  mathematical  assurance  that 
— "  It  is  as  sure  that  collisions  must  occur  between  great 
masses  moving  through  space,  as  it  is  that  ships,  steered 
without  intelligence  directed  to  prevent  collision,  could 
not  cross  and  recross  the  Atlantic  for  thousands  of  years 
with  immunity  from  collision." 

The  author  of*  the  paper  in  the  Cornhill  denies  this 
very  positively,  and  without  going  into  the  mathematical 
details,  points  out  the  basis  upon  which  it  may  be  mathe- 
matically refuted — viz.,  that  all  such  worlds  are  traveling  in 
fixed  or  regular  orbits  around  their  primaries  or  suns, 
while  each  of  these  primaries  travels  in  its  own  necessary 
path,  carrying  with  it  all  its  attendants,  which  still  move 
about  him,  just  as  though  he  had  no  motion  of  his  own. 

These  are  the  conclusions  of  Newtonian  dynamics,  the  sub- 
lime simplicity  of  which  contrasts  so  curiously  with  the  com- 
plex dreams  of  the  modern  atom-splitters,  and  which  make 
a  further  and  still  more  striking  contrast  by  their  exact  and 
perfect  accordance  with  actual  and  visible  phenomena. 

Newton  has  taught  us  that  there  can  be  no  planets  trav- 
eling at  random  like  the  Sir  TV.  Thomson's  imaginary 
ships  with  blind  pilots,  and  by  following  up  his  reasoning, 
we  reach  the  conclusion,  that  among  all  the  countless  mil- 
lions of  worlds  that  people  the  infinity  of  space,  there  is 
no  more  risk  of  collision  than  there  is  between  any  two  of 
the  bodies  that  constitute  our  own  solar  system. 

All  the  observations  of  astronomers,  both  before  and 
since  the  discovery  of  the  telescope,  confirm  this  conclu- 
sion. The  long  nightly  watching  of  the  Chaldean  shep- 
herds, the  star-counting,  star-gauging,  star-mapping,  and 
other  laborious  gazing  of  mediaeval  and  modern  astrono- 
mers, have  failed  to  discover  any  collision,  or  any  motion 
tending  to  collision,  among  the  myriads  of  heavenly  bodies 
whose  positions  and  movements  have  been  so  faithfully  and 
diligently  studied.  Thus,  the  hypothesis  of  creation  which 
demands  the  destruction  of  two  Avorlds  in  order  to  effect 
the  sowing  of  a  seed,  is  as  inconsistent  with  sound  dynam- 
ics as  it  is  repugnant  to  common  sense. 


This  subject  suggests  a  similar  one,  which  was  discussed 
a  few  months  since  at  the  Acadamy  of  Sciences  of  Paris. 
On  January  30th  last  M.  St.  Meunier  read  a  paper  on  "  The 
mode  of  rupture  of  a  star,  from  which  meteors  are  de- 
rived." The  author  starts  with  .the  assumption  that  me- 
teors have  been  produced  by  the  rupture  of  a  world,  basing 
this  assumption  upon  the  arguments  he  has  stated  in  pre- 
vious papers.  He  discards  altogether  Sir  "W.  Thomson's 
idea  of  a  collision  between  two  worlds,  but  works  out  a  con- 
clusion quite  as  melancholy. 

He  begins,  like  most  other  builders  of  cosmical  theories, 
with  the  hypothesis  that  this  and  all  the  other  worlds  of 
space  began  their  existence  in  a  condition  of  nebulous  in- 
fancy; that  they  gradually  condensed  into  molten  liquids, 
and  then  cooled  down  till  they  obtained  a  thin  outside 
crust  of  solid  matter,  resting  upon  a  molten  globe  within; 
that  this  crust  then  gradually  thickened  -as  the  world 
grew  older  and  cooled  down  by  radiation.  I  will  not  stop 
to  discuss  this  nebular  and  cooling-down  hypothesis  at 
present,  though  it  is  but  fair  to  state  that  "I "don't  believe 
a  bit  of  it." 

Taking  all  this  for  granted — a  considerable  assumption — 
M.  St.  Meunier  reasons  very  ably  upon  what  must  follow,  if 
we  further  assume  that  each  world  is  somehow  supplied 
with  air  and  water,  and  that  the  atmosphere  and  the  ocean 
of  each  world  are  limited  and  unconnected  with  those  of 
any  other  world,  or  with  any  general  interstellar  medium. 

What,  then,  will  happen  as  worlds  grow  old?  As  they 
cool  down,  they  must  contract;  the  liquid  inside  can  man- 
age this  without  any  inconvenience  to  itself,  but  not  so 
with  the  outer  spherical  shell  of  solid  matter.  As  the 
inner,  or  hotter  part  of  this  contracts,  the  cool  outside 
must  crumple  up  in  order  to  follow  it,  and  thus  mountain 
chains  and  great  valleys,  lesser  hills  and  dales,  besides 
faults  and  slips,  dykes,  earthquakes,  volcanoes,  etc.,  are 
explained. 

According  to  M.  St.  Meunier,  the  moon  has  reached  a 
more  advanced  period  of  cosmical  existence  than  the  earth. 
She  is  our  senior;  and  like  the  old  man  who  shows  hi.s 
gray  hairs  and  tottering  limbs  to  inconsiderate  youth,  she 


260  SCIENCE  IN  SHORT  CHAPTERS. 

shines  a  warning  upon  our  gay  young  world,  telling  her 
that — 

Let  her  paint  an  inch  thick,  to  this  favor  she  must  come 

— that  the  air  and  ocean  must  pass  away,  that  all  the  living 
creatures  of  the  earth  must  perish,  and  the  desolation  shall 
come  about  in  this  wise. 

At  present,  the  interior  of  our  planet  is  described  as  a 
molten  fluid,  with  a  solid  crust  outside.  As  the  world 
cools  down  with  age,  this  crust  will  thicken  and  crack,  and 
orack  again,  as  the  lower  part  contracts.  This  will  form 
rainures,  i.e.,  long  narrow  chasms,  of  vast  depth,  which, 
like  those  on  the  moon,  will  traverse,  without  deviation, 
the  mountains,  valleys,  plains,  and  ocean-beds;  the  waters 
will  fall  into  these,  and,  after  violent  catastrophes,  arising 
from  their  boiling  by  contact  with  the  hot  interior,  they 
will  finally  disappear  from  the  surface,  and  become  ab- 
sorbed in  the  pores  of  the  vastly-thickened  earth-crust,  and 
in  the  caverns,  cracks,  and  chasms  which  the  rending  con- 
traction will  open  in  the  interior.  These  cavities  will  con- 
tinue to  increase,  will  become  of  huge  magnitude  when  the 
outside  crust  grows  thick  enough  to  form  its  own  support- 
ing arch,  for  then  the  fused  interior  will  recede,  and  form 
mighty  vaults  that  will  engulf  not  the  waters  merely,  but 
all  the  atmosphere  likewise. 

At  this  stage  the  earth,  according  to  M.  St.  Meunier,  will 
be  a  middle-aged  world  like  the  moon;  but  as  old  age  ad- 
vances the  contraction  of  the  fluid,  or  viscous  interior  be- 
neath the  outside  solid  crust  will  continue,  and  the  rain- 
ures will  extend  in  length  and  depth  and  width,  as  he  main- 
tains they  are  now  growing  in  the  moon.  This,  he  says, 
must  continue  till  the  centre  solidifies,  and  then  these 
cracks  will  reach  that  centre,  and  the  world  will  be  split 
through  in  fragments  corresponding  to  the  different  rain- 
ures. 

Thus  we  shall  have  a  planet  composed  of  several  solid 
fragments  held  together  only  by  their  mutual  attractions, 
but  the  rotary  movement  of  these  will,  according  to  the 
French  philosopher,  become  unequal,  as  "the  fragments 


DYING  TREES  IN  KENSINGTON  GARDENS.      261 

present  different  densities,  and  are  situated  at  unequal  dis- 
tances from  the  centre;  some  will  be  accelerated,  others 
retarded;  they  will  rub  against  each  other,  and  grind  away 
those  portions  which  have  the  weakest  cohesion."  The 
fragments  thus  worn  off  will,  "at  the  end  of  sufficient 
time,  girdle  with  a  complete  ring  the  central  star."  At 
this  stage  the  fragments  become  real  meteors,  and  then 
perform  all  the  meteoric  functions  excepting  the  seed-car- 
rying of  Sir  W.  Thomson. 

It  would  be  an  easy  task  to  demolish  these  speculations, 
though  not  within  the  space  of  one  of  my  letters.  A  glance 
at  the  date  of  this  paper,  and  the  state  of  Paris  and  the 
French  mind  at  the  time,  may,  to  some  extent,  explain 
the  melancholy  relish  with  which  the  Parisian  philosopher 
works  out  his  doleful  speculations.  Had  the  French  army 
marched  vigorously  to  Berlin,  I  doubt  whether  this  paper 
would  ever  have  found  its  way  into  the  "  Comptes  Eendus." 
After  the  fall  of  Paris,  and  the  wholesale  capitulation  of 
the  French  armies,  it  was  but  natural  that  a  patriotic 
Frenchman,  howsoever  strong  his  philosophy,  should  spec- 
ulate on  the  collapse  of  all  the  stars,  and  the  general  wind- 
ing-up  of  the  universe. 


THE  DYING  TREES  IN  KENSINGTON  GARDENS. 

A  GREAT  many  trees  have  lately  been  cut  down  in  Ken- 
sington Gardens;  and  the  subject  was  brought  before  the 
House  of  Commons  at  the  latter  part  of  its  last  session. 
In  reply  to  Mr.  Ritchie's  question,  Mr.  Adam,  the  then 
First  Commissioner  of  Works,  made  explanations  which, 
so  far  as  they  go,  are  satisfactory — but  the  distance  is  very 
small.  He  states  that  all  who  have  watched  the  trees  must 
have  seen  that  their  decay  "has  become  rapid  and  decided 
in  the  last  two  years,"  that  when  the  vote  for  the  parks 
came  on  many  "were  either  dead  or  hopelessly  dying," 
that  in  the  more  thickly  planted  portions  of  the  gardens 
the  trees  were  dead  and  dying  by  hundreds,  owing  to  the 


262  SCIENCE  IN  SHORT  CHAPTERS. 

impoverished  soil  and  the  terrible  neglect  of  timely  thin- 
ning fifty  or  sixty  years  ago. 

Knowing  the  sensitiveness  of  the  public  regarding  tree- 
cutting,  Mr.  Adam  obtained  the  co-operation  of  a  commit- 
tee of  experts,  consisting  of  Sir  Joseph  Hooker,  Mr. 
Glutton,  and  Mr.  Thomas,  "  so  distinguished  as  a  landscape 
gardener,"  and  the  late  First  Commissioner  of  Works. 
They  had  several  meetings,  and,  as  Mr.  Adam  informs  us, 
"  the  result  has  been  a  unanimous  resolution  that  we  ought 
to  proceed  at  once  to  clear  away  the  dead  and  dying  trees." 
This  is  being  done  to  the  extent  of  "  an  absolute  clearance" 
in  some  places,  and  the  removal  of  numerous  trees  all  over 
the  gardens.  We  are  further  told  that  "  the  spaces  cleared 
will  either  be  trenched,  drained,  and  replanted,  or  will  be 
left  open,  as  may  appear  best."  Mr.  Adam  adds  that  "the 
utmost  care  is  being  used  in  the  work;  that  not  a  tree  is 
being  cut  that  can  properly  be  spared;  and  that  every  effort 
will  be  made  to  restore  life  to  the  distinguished  trees  that 
are  dying." 

I  have  watched  the  proceedings  in  Kensington  Gardens 
and  also  in  Bushey  Park,  and  have  considerable  difficulty 
in  describing  the  agricultural  vandalism  there  witnessed, 
and  expressing  my  opinion  on  it,  without  transgressing  the 
bounds  of  conventional  courtesy  towards  those  who  are  re- 
sponsible. I  do  not  refer  to  the  cutting  down  of  the  dead 
and  dying  trees,  but  to  the  proceedings  by  which  they 
have  been  officially  and  artificially  killed  by  those  who 
ought  to  possess  sufficient  knowledge  of  agricultural  chem- 
istry to  understand  the  necessary  consequences  of  their 
conduct. 

About  forty  years  have  elapsed  since  Liebig  taught  to  all 
who  were  able  and  willing  to  learn  that  trees  and  other 
vegetables  are  composed  of  two  classes  of  material:  1st, 
the  carbon  and  elements  of  water  derived  from  air  and  rain ; 
and  2d,  the  nitrogenous  and  incombustible  saline  com- 
pounds derived  from  the  soil.  The  possible  atmospheric 
origin  of  some  of  the  nitrogen  is  still  under  debate,  but 
there  is  no  doubt  that  all  which  remains  behind  as  incom- 
bustible ash,  when  we  burn  a  leaf,  is  so  much  matter  taken 
out  of  the  soil.  Every  scientific  agriculturist  knows  that 


DYING   TREES  IN  KENSINGTON  GARDENS.      263 

certain  crops  take  away  certain  constituents  from  the  soil, 
and  that  if  this  particular  cropping  continues  without  a 
replacing  of  those  particular  constituents  of  fertility,  the 
soil  must  become  barren  in  reference  to  the  crop  in  ques- 
tion, though  other  crops  demanding  different  food  may 
?t  ill  grow  upon  it. 

The  agricultural  vandalism  that  I  have  watched  with  so 
much  vexation  is  the  practice  of  annually  raking  and 
sweeping  together  the  fallen  leaves,  collecting  them  in 
barrows  and  carts,  and  then  carrying  them  quite  away  from 
the  soil  in  which  the  trees  are  growing,  or  should  grow.  I 
have  inquired  of  the  men  thus  employed  whether  they  put 
anything  on  the.  ground  to  replace  these  leaves,  and  they 
have  not  merely  replied  in  the  negative,  but  have  been 
evidently  surprised  at  such  a  question  being  asked.  What 
is  finally  done  with  the  leaves  I  do  not  know;  they  may  be 
used  for  the  flower-beds  or  sold  to  outside  florists.  I  have 
seen  a  large  heap  accumulated  near  to  the  Round  Pond. 

Now,  the  leaves  of  forest  trees  are  just  those  portions 
containing  the  largest  proportion  of  ash;  or,  otherwise 
stated,  they  do  the  most  in  exhausting  the  soil.  In  Epping 
Forest,  in  the  New  Forest,  and  other  forests  where  there 
has  been  still  more  "  terrible  neglect  of  timely  thinning," 
the  trees  continue  to  grow  vigorously,  and  have  thus  grown 
for  centuries;  the  leaves  fall  on  the  soil  wherein  the  trees 
grow,  and  thus  continually  return  to  it  all  they  have  taken 
away. 

They  do  something  besides  this.  During  the  winter" 
they  gradually  decay.  This  decay  is  a  process  of  slow  com- 
bustion, giving  out  just  as  much  heat  as  though  all  the 
leaves  were  gathered  together  and  used  as  fuel  for  a  bon- 
fire; but  the  heat  in  the  course  of  natural  decay  is  gradually 
given  out  just  when  and  where  it  is  wanted,  and  the  coat- 
ing of  leaves,  moreover,  forms  a  protecting  winter  jacket 
to  the  soil. 

I  am  aware  that  the  plea  for  this  sweeping-up  of  leaves 
is  the  demand  for  tidiness;  that  people  with  thin  shoes 
might  wet  their  feet  if  they  walked  through  a  stratum  of 
fallen  leaves.  The  reply  to  this  is  that  all  reasonable  de- 
mands of  this  class  would  be  satisfied  by  clearing  the  foot- 


264  SCIENCE  IN  SHORT  CHAPTERS. 

paths,  from  which  nobody  should  deviate  in  the  winter  time. 
Before  the  season  for  strolling  in  the  grass  returns,  Nature 
will  have  disposed  of  the  fallen  leaves.  A  partial  remedy 
may  be  applied  by  burning  the  leaves,  then  carefully  dis- 
tributing their  ashes;  but  this  is  after  all  a  clumsy  imita- 
tion of  the  natural  slow  combustion  above  described,  and  is 
wasteful  of  the  ammoniacal  salts  as  well  as  of  the  heat. 
The  avenues  of  Bushey  Park  are  not  going  so  rapidly  as 
the  old  sylvan  glories  of  Kensington  Gardens,  though  the 
same  robbery  of  the  soil  is  practiced  in  both  places.  I 
have  a  theory  of  my  own  in  explanation  of  the  difference, 
viz.,  that  the  cloud  of  dust  that  may  be  seen  blowing  from 
the  roadway  as  the  vehicles  drive  along  the  Chestnut  Ave- 
nue of  Bushey  Park,  settles  down  on  one  side  or  the  other, 
and  supplies  material  which  to  some  extent,  but  not  suffi- 
ciently, compensates  for  the  leaf -robbery. 

The  First  Commissioner  speaks  of  efforts  being  made  to 
restore  life  to  the  distinguished  trees  that  are  dying.  Let 
us  hope  that  these  include  a  restoration  to  the  soil  of  those 
particular  salts  that  have  for  some  years  past  been  annually 
carted  away  from  it  in  the  form  of  dead  leaves,  and  that 
this  is  being  done  not  only  around  the  "  distinguished " 
trees,  but  throughout  the  gardens. 

Any  competent  analytical  chemist  may  supply  Mr.  Adam 
with  a  statement  of  what  are  these  particular  salts.  This 
information  is  obtainable  by  simply  burning  an  average 
sample  of  the  leaves  and  analyzing  their  ashes. 

While  on  this  subject  I  may  add  a  few  words  on  an- 
.  other  that  is  closely  connected  with  it.  In  some  parts 
of  the  parks  gardeners  may  be  seen  more  or  less  ener- 
getically occupied  in  pushing  and  pulling  mowing-machines; 
and  carrying  away  the  grass  which  is  thus  cut.  This 
produces  the  justly  admired  result  of  a  beautiful  velvet 
lawn;  but  unless  the  continuous  exhaustion  of  the  soil 
is  compensated,  a  few  years  of  such  cropping  will  starve  it. 
This  subject  is  now  so  well  understood  by  all  educated 
gardeners  that  it  should  be  impossible  to  suppose  it  to  be 
overlooked  in  our  parks,  as  it  is  so  frequently  in  domestic 
gardening.  Many  a  lawn  that  a  few  years  ago  was  the 
pride  of  its  owner  is  now  becoming  as  bald  as  the  head 


DYING   TREES  IN  KENSINGTON  GARDENS.     265 

of  the  faithful,  "practical,"  and  obstinate  old  gardener 
who  so  heartily  despises  the  "fads"  of  scientific  theorists. 

When  natural  mowing-machines  are  used,  i.e.,  cattle  and 
sheep,  their  droppings  restore  all  that  they  take  away  from 
the  soil,  minus  the  salts  contained  in  their  own  flesh,  or  the 
inil'k  that  may  be  removed.  An  interesting  problem  has 
been  for  some  time  past  under  the  consideration  of  the 
more  scientific  of  the  Swiss  agriculturists.  From  the 
mountain  pasturages  only  milk  is  taken  away,  but  this 
milk  contains  a  certain  quantify  of  phosphates,  the  resto- 
ration of  which  must  be  effected  sooner  or  later,  or  the 
produce  will  be  cut  off,  especially  now  that  so  much  con- 
densed milk  is  exported. 

The  wondrously  rich  soil  of  some  parts  of  Virginia  has 
been  exhausted  by  unrequited  tobacco  crops.  The  quan- 
tity of  ash  displayed  on  the  burnt  end  of  a  cigar  demon- 
strates the  exhausting  character  of  tobacco  crops.  That 
which  the  air  and  water  supplied  to  the  plant  is  returned 
as  invisible  gases  during  combustion,  but  all  the  ash  that 
remains  represents  what  the  leaves  have  taken  from  the 
soil,  and  what  should  be  restored  in  order  to  sustain  its 
pristine  fertility. 

The  West  India  Islands  have  similarly  suffered  to  a  vejy 
serious  extent  on  account  of  the  former  ignorance  of  the 
the  sugar  planters,  who  used  the  canes  as  fuel  in  boiling 
down  the  syrup,  and  allowed  the  ashes  of  those  canes  to  be 
washed  into  the  sea.  They  were  ignorant  of  the  fact  that 
pure  sugar  maybe  taken  away  in  unlimited  quantities  with- 
out any  impoverishment  of  the  land,  seeing  that  it  is  com- 
posed merely  of  carbon  and  the  elements  of  water,  all  de- 
rivable from  air  and  ruin.  All  that  is  needed  to  maintain 
the  perennial  fertility  of  a  sugar  plantation  is  to  restore  the 
stems  and  leaves  of  the  cane,  or  carefully  to  distribute  their 
ashes. 

The  relation  of  these  to  the  soil  of  the  sugar  plantations  is 
precisely  the  same  as  that  of  the  leaves  of  the  trees  to  the 
soil  of  Kensington  Gardens,  and  the  reckless  removal  of 
either  must  produce  the  same  disastrous  consequences. 


266  SCIENCE  IN  SHORT  CHAPTERS. 


THE  OLEAGINOUS  PEODUCTS  OF  THAMES 
MUD:  WHERE  THEY  COME  FROM  AND 
WHERE  THEY  GO. 

OJSTCE  upon  a  time — and  not  a  very  long  time  since — a 
French  chemist  left  the  land  of  superexcellence,  and  crossed 
to  the  shores  of  foggy  Albion.  He  proceeded  to  Yorkshire, 
his  object  being  to  make  hfs  fortune.  He  was  so  presump- 
tuous as  to  believe  that  he  might  do  this  by  picking  up 
something  which  Yorkshiremen  threw  away.  That  some- 
thing was  soapsuds.  His  chemistry  taught  him  that  soap 
is  a  compound  of  fat  and  alkali,  and  that  if  a  stronger  acid 
than  that  belonging  to  the  fat  is  added  to  soapsuds,  the 
stronger  acid  will  combine  with  the  alkali  and  release  the 
fat,  the  which  fat  thus  liberated  will  float  upon  the  surface 
of  the  liquid,  and  may  then  be  easily  skimmed  off,  melted 
together,  and  sold  at  a  handsome  profit. 

But  why  leave  the  beautiful  France  and  desolate  himself 
in  dreary  Yorkshire  merely  to  do  this?  His  reason  was, 
that  the  clothworkers  of  Yorkshire  use  tons  and  tons  of 
soap  for  scouring  their  materials,  and  throw  away  millions 
of  gallons  of  soapsuds.  Besides  this,  there  are  manufacto- 
ries of  sulphuric  acid  near  at  hand,  and  a  large  demand  for 
machinery  grease  just  thereabouts.  He  accordingly  bought 
iron  tanks,  and  erected  works  in  the  midst  of  the  busiest 
centre  of  the  woolen  manufacture.  But  he  did  not  make 
his  fortune  all  at  once.  On  the  contrary,  he  failed  to  pay 
expenses,  for  in  his  calculations  he  had  omitted  to  allow 
for  the  fact  that  the  soap  liquor  is  much  diluted,  and  there- 
fore he  must  carry  much  water  in  order  to  obtain  a  little 
fat.  This  cost  of  carriage  ruined  his  enterprise,  and  his 
works  were  offered  for  sale. 

The  purchaser  was  a  shrewd  Yorkshireman,  who  then 
was  a  dealer  in  second-hand  boilers,  tanks,  and  other  iron 
wares.  When  he  was  about  to  demolish  the  works,  the 
Frenchman  took  him  into  confidence,  and  told  the  story  of 
his  failure.  The  Yorkshireman  said  little,  but  thought 
much;  and  having  finally  assured  himself  that  the  carriage 


OLEAGINOUS  PRODUCTS  OF  THAMES  MUD.     267 

was  the  only  difficulty,  he  concluded,  after  the  manner  of 
Mahomet,  that  if  the  mountain  would  not  come  to  him,  he 
might  go  to  the  mountain;  and  then  made  an  offer  of 
partnership  on  the  basis  that  the  Frenchman  should  do  the 
chemistry  of  the  work,  and  that  he  (the  Yorkshireman) 
should  do  the  rest. 

Accordingly,  he  went  to  the  works  around,  and  offered 
to  contract  for  the  purchase  of  all  their  soapsuds,  if  they 
would  allow  him  to  put  up  a  tank  or  two  on  their  premises. 
This  he  did;  the  acid  was  added,  the  fat  rose  to  the  sur- 
face, was  skimmed  off,  and  carried,  without  the  water,  to 
the  central  works,  where  it  was  melted  down,  and,  with 
very  little  preparation,  was  converted  into  "  cold-neck 
grease,"  and  "hot-neck  grease,"  and  used,  besides,  for 
other  lubricating  purposes.  The.  Frenchman's  science  and 
skill,  united  with  the  Yorkshireman's  practical  sagacity, 
built  up  a  flourishing  business,  and  the  grease  thus  made  is 
still  in  great  demand  and  high  repute  for  lubricating  the 
rolling-mills  of  iron  works,  and  for  many  other  kinds  of 
machinery. 

My  readers  need  not  be  told  that  there  are  soapsuds  in 
London  as  well  as  in  Yorkshire,  and  they  also  know  that 
the  London  soapsuds  pass  down  the  drains  into  the  sewers. 
I  may  tell  them  that  betides  this  there  are  many  kinds  of 
acids  also  passed  into  London  sewers,  and  that  others  are 
generated  by  the  decompositions  there  abounding.  These 
acids  do  the  Frenchman's  work  upon  the  London  soapsuds, 
but  the  separated  fat,  instead  of  rising  slowly  and  undis- 
turbed to  form  a  film  upon  the  surface  of  the  water,  is 
rolled  and  tumbled  amongst  its  multifarious  companion 
filth,  and  it  sticks  to  whatever  it  may  find  congenial  to  it- 
self. Hairs,  rags,  wool,  ravellings  of  cotton,  and  fibres  of 
all  kinds  are  especially  fraternal  to  such  films  of  fat:  they 
lick  it  up  and  stick  it  about  and  amid  themselves;  and  as 
they  and  the  fat  roll  and  tumble  along  the  sewers  together, 
they  become  compounded  and  shaped  into  unsavory  balls 
that  are  finally  deposited  on  the  banks  of  the  Thames,  and 
quietly  repose  in  its  hospitable  mud. 

But  there  is  no  peace  even  there,  and  the  gentle  rest  of 
the  fat  nodules  is  of  short  duration.  The  mud-larks  are 


268  SCIENCE  IN  SHORT  CHAPTERS. 

down  upon  them,  in  spite  of  all  their  burrowing;  they  are 
gathered  up  and  melted  down.  The  filthiest  of  their  asso- 
ciated filth  is  thus  removed,  and  then,  and  with  a  very  little 
farther  preparation,  they  appear  as  cakes  of  dark-colored 
hard  fat,  very  well  suited  for  lubricating  machinery,  and 
indifferently  fit  for  again  becoming  soap,  and  once  more 
repeating  their  former  adventures. 

Those  gentlemen  of  the  British  press  whose  brilliant 
imagination  supplies  the  public  with  their  intersessional 
harvests  of  sensational  adulteration  panics,  have  obtained  a 
fertile  source  of  paragraphs  by  co-operating  with  the  mud- 
larks in  the  manufacture  of  butter  from  Thames  umd. 

The  origin  of  these  stories  is  traceable  to  certain  officers 
of  the  Thames  police,  who,  having  on  board  some  of  these 
gentlemen  of  the  press  engaged  in  hunting  up  information 
respecting  a  body  found  in  the  river,  supplied  their  guests 
with  a  little  supplementary  chaff  by  showing  them  a  mud- 
lark's gatherings,  and  telling  them  that  it  was  raw  material 
from  which  "tine  Dorset"  is  produced.  A  communication 
from  "  Our  Special  Correspondent"  on  the  manufacture  of 
butter  from  Thames  mud  accordingly  appeared  in  the  atro- 
city column  on  the  following  morning,  and  presently  "  went 
the  round  of  the  papers." 

Although  -it  is  perfectly  possible  by  the  aid  of  modern 
chemical  skill  to  refine  even  such  filth  as  this,  and  to  churn 
it  into  a  close  resemblance  to  butter,  the  cost  of  doing  so 
would  exceed  the  highest  price  obtainable  for  the  finest 
butter  that  comes  to  the  London  market.  A  skillful  chem- 
ist can  convert  all  the  cotton  fibres  that  are  associated  with 
this  sewage  fat  into  pure  sugar  or  sugar-candy,  but  the 
manufacture  of  sweetmeats  from  Thames  mud  would  not 
pay  any  better  than  the  production  of  butter  from  the  same 
source,  and  for  the  same  reason. 

Glutton-suet,  chop-parings,  and  other  clean,  wholesome 
fat  can  be  bought  wholesale  for  less  than  fivepence  per 
pound.  It  would  cost  above  three  times  as  much  as  this  to 
bring  the  fat  nodules  of  the  Thames  mud  to  as  near  an 
approach  to  butter  as  this  sort  of  fat.  Therefore  the  Thames 
mud-butter  material  would  be  three  times  as  costly  as  that 
obtainable  from  the  butcher.  While  the  supply  of  mutton- 


LUMINOUS  PAINT.  269 

suet  is  so  far  in  excess  of  the  butter-making  demand  that 
tons  of  it  are  annually  used  in  the  North  for  lubricating 
machinery,  we  need  not  fear  that  anything  less  objectionable 
— i.e.,  more  costly  to  purify — will  be  used  as  a  butter 
substitute. 


LUMINOUS    PAINT. 

THE  sun  is  evidently  going  out  of  fashion,  and  is  more  and 
more  excluded  from  "good  society"  as  our  modern  substi- 
tute for  civilization  advances.  "Serve  him  right!"  many 
will  say,  for  behaving  so  badly  during  the  last  two  summers. 
The  old  saw,  which  says  something  about. "early  to  bed 
and  early  to  rise"  is  forgotten:  we  take  "luncheon"  at 
dinner-time,  dine  at  supper-time,  make  "  morning"  calls 
and  goto  "morning"  concerts,  etc.,  late  in  the  afternoon, 
say  ' '  Good  morning"  until  6  or  7  P.  M.  ;  and  thus,  by 
sleeping  through  the  bright  hours  of  the  morning,  and 
waking  up  fully  only  a  little  before  sunset,  the  demand  for 
artificial  light  becomes  almost  overwhelming.  Not  only  do 
we  require  this  during  a  longer  period  each  day,  but  we 
insist  upon  more  and  more,  and  still  more  yet,  during  that 
period. 

The  rushlight  of  our  forefathers  was  superseded  by  an 
exotic  luxury,  the  big-flame  candle  made  of  Russian  tallow, 
with  a  wick  of  Transatlantic  cotton.  Presently  this  luxu- 
rious innovation  was  superseded  by  the  "mould  candle  ;" 
the  dip  was  consigned  to  the  kitchen,  and  the  bloated  aris- 
tocrats of  the  period  indulged  in  a  pair  of  candlesticks, 
alarming  their  grandmothers  by  the  extravagance  of  burn- 
ing two  candles  on  one  table.  Presently  the  mould  candle 
was  snuffed  out  by  the  composite ;  then  came  the  trans- 
lucent pearly  paraffin  caudle,  gas  light,  solar  lamps,  mod- 
erator lamps,  and  paraffin  lamps.  Even  these,  with  their 
brilliant  white  flame  from  a  single  wick,  are  now  insufficient, 
and  we  have  duplex  and  even  triplex  wicks  to  satisfy  our 
demand  for  glaring  mockeries  of  the  departed  sun. 

•Some  are  still  living  who  remember  the  oil  lamps  in 


270  SCIENCE  IN  SHORT  CHAPTERS. 

Cheapside  and  Piccadilly,  and  the  excitement  caused  by 
the  brilliancy  of  the  new  gas  lamps ;  but  now  we  are  dissat- 
isfied with  these,  and  demand  electric  lights  for  common 
thoroughfares,  or  some  extravagant  combination  of  con- 
centric or  multiplex  gas-jets  to  rival  it. 

The  latest  novelty  is  a  device  to  render  darkness  visible 
by  capturing  the  sunbeams  during  the  day,  holding  them 
as  prisoners  until  after  sunset,  and  then  setting  them  free 
in  the  night.  The  principle  is  not  a  new  discovery ;  the 
novelty  lies  in  the  application  and  some  improvements  of 
detail.  In  the  "Boy's  Own  Book,"  or  "Endless  Amuse- 
ment," of  thirty  or  forty  years  ago,  are  descriptions  of 
"Canton's  phosphorus,"  or  "solar  phosphori,"  and  recipes 
for  making  them.  Burnt  oyster-shells  or  oyster-shells 
burnt  with  sulphur,  was  one  of  these. 

Various  other  methods  of  effecting  combination  between 
lime  or  baryta  with  sulphur  are  described  in  old  books,  the 
result  being  the  formation  of  more  or  less  of  what  modern 
chemists  call  calcium  sulphide  and  barium  sulphide  (or 
otherwise  sulphide  of  calcium  or  .sulphide  of  barium). 
These  compounds,  when  exposed  to  the  sun,  are  mysteri- 
ously acted  upon  by  the  solar  rays,  and  put  into  such  a 
condition  that  their  atoms  or  molecules,  or  whatever  else 
constitutes  their  substance,  are  set  in  motion — in  that  sort 
of  motion  which  communicates  to  the  surrounding  medium 
the  Avavy  tremor  which  agitates  our  optic  nerve  and  pro- 
duces the  sensation  of  light. 

Until  lately,  this  property  has  served  no  other  purpose 
than  puzzling  philosophers,  and  amusing  that  class  of  boys 
who  burn  their  fingers,  spoil  their  clothes,  and  make  holes 
in  their  mothers'  table-covers,  with  sulphuric  acid,  nitric 
acid,  and  other  noxious  chemicals.  The  first  idea  of  turn- 
ing it  to  practical  account  was  that  of  making  a  sort  of 
enamel  of  one  or  the  other  of  these  sulphides,  and  using  it 
as  a  coating  for  clock-faces.  A  surface  thus  coated  and 
exposed  to  the  light  during  the  day  becomes  faintly  lumi- 
nous at  night. 

Anybody  desirous  of  seeing  the  sort  of  light  which  it 
emits,  may  do  so  very  easily  by  purchasing  an  unwashed 
smelt  from  the  fishmonger,  and  allowing  it  to  dry  with  its 


LUMINOUS  PAINT.  271 

natural  slime  upon  it,  then  looking  at  it  in  the  dark.  A 
sole  or  almost  any  other  fish  will  answer  the  purpose,  but  I 
name  the  smelt  from  having  found  it  the  most  reliable  in 
the  course  of  my  own  experiments.  It  emits  a  dull,  ghostly 
light,  with  very  little  penetrating  power,  which  shows  the 
shape  of  the  fish,  but  casts  no  perceptible  light  on  objects 
around. 

Thus  the  phosphorescent  parish-clock  face,  with  non- 
phosphorescent  figures  and  hands,  would  look  like  a  pale 
ghost  of  the  moon  with  dark  figures  round  it,  and  dark 
hands  stretching  across,  by  which  the  time  of  the  night 
might  possibly  be  discovered  there  or  thereabouts.  This 
invention  has  already  appeared  in  a  great  many  para- 
graphs, but,  hitherto,  upon  very  few  clock-faces. 

Eecently  it  has  assumed  a  more  ambitious  form — 
patented,  of  course.  The  patentees  claim  an  improved 
phosphorescent  powder,  which  is  capable  of  being  worked 
up  with  the  medium  of  paints  and  varnishes,  and  thus 
applied,  not  merely  to  clock-faces,  but  to  the  whole  of  the 
walls  and  ceilings  of  any  apartment.  In  this  case  the  faint- 
ness  of  the  light  will  be  in  some  degree  compensated  by  the 
extent  of  phosphorescent  surface,  and  it  is  just  possible 
that  the  sum  total  of  the  light  emitted  from  walls  and 
ceiling  may  be  nearly  equal  to  that  of  one  mould  candle. 
If  so,  it  will  have  somewlue  as  a  means  of  lighting  powder 
magazines  and  places  for  storage  of  inflammable  compounds. 
It  is  stated  that  one  of  the  London  Dock  companies  is 
about  to  use  it  for  its  spirit  vaults  ;  also  that  the  Admiralty 
has  already  tried  the  paint  at  Whitehall,  and  has  ordered 
two  compartments  of  the  Cornus  to  be  painted  with  it,  in 
order  to  test  its  capability  of  lighting  the  dark  regions  of 
ironclad  ships. 

This  application  can,  however,  only  be  limited  to  those 
parts  which  receive  a  fair  amount  of  light  during  the  day, 
for  unless  the  composition  first  receives  light,  it  is  not  able 
afterwards  to  emit  it,  and  this  emission  or  phosphorescence 
only  continues  a  few  hours  after  the  daylight  has  passed 
away  ;  five  or  six  hours  is  the  time  stated. 

A  theatrical  manager  is  said  to  be  negotiating  for  the  ex- 
clusive right  to  employ  this  weird  illumination  for  scenic 


272  SCIENCE  IN  SHORT  CHAPTERS. 

purposes.  The  sepulchre  scene  in  "  Robert  le  Diable,"  or 
the  incantation  in  "Der  Freischutz,"  or  "The  Sorcerer," 
might  be  made  especially  effective  by  its  ghostly  aid.  The 
name-plates  of  streets,  and  buoys  at  sea  might  be  advan- 
tageously coated  with  such  a  composition;  and  many  other 
uses  suggest  themselves. 

There  are  rival  inventors,  as  a  matter  of  course.  The 
French  patentees  claim  the  use  of  cuttle-fish  bones,  various 
sea-shells,  etc.,  mixed  with  pure  lime,  sulphur,  and  calcined 
sea-salt,  besides  sulphides  of  calcium,  barium,  strontium, 
uranium,  magnesium,  or  aluminium.  They  also  add  phos- 
phorus itself,  though  for  what  purpose  is  questionable,  see- 
ing that  this  substance  is  only  luminous  during  the  course 
of  its  oxidation  or  slow  combustion,  and  after  this  has  ended 
the  resultant  phosphoric  acid  is  no  more  luminous  than 
linseed  oil  or  turpentine.  An  admixture  of  phosphorus 
might  temporarily  increase  the  luminosity  of  a  sample,  but 
any  conclusions  based  upon  this  would  be  quite  delusive. 
They  also  assert  that  electrical  discharges  passed  through 
the  paint  increase  its  luminosity.  According  to  some  en- 
thusiasts, electricity  is  to  do  everything ;  but  these  ladies 
and  gentlemen  omit  to  calculate  the  cost  of  rousing  and 
feeding  this  omnipotent  giant.  In  this  case  electrical  ma- 
chinery for  stimulating  the  paint  for  anything  outside  of 
lecture-table  experiments  or  theatrical  and  other  sensational 
displays,  would  be  a  commercial  absurdity. 

The  Americans,  of  course,  are  re-inventing  in  this  direc- 
tion, but  Mr.  Edison  has  not  yet  appeared  on  the  luminous- 
paint  scene.  If  he  does  we  shall  doubtless  hear  of  some- 
thing very  brilliant,  even  though  we  never  see  it.  In  the 
meantime  we  may  safely  hope  that  this  application  of  an 
old  .scientific  plaything  to  useful  purposes  may  become  of 
considerable  utility,  as  it  evidently  opens  a  wide  field  for 
further  investigation  and  progressive  improvement,  by  the 
application  of  the  enlarged  powers  which  modern  science 
places  at  the  disposal  of  ingenious  inventors.  We  hope, 
for  the  sake  of  all  concerned,  that  it  will  not  fall  into  the 
hands  of  professional  prospectus  manufacturers  and  joint- 
stpck-company  mongers,  and  that  the  story  of  its  triumphs 
will  be  told  without  any  newspaper  exaggerations. 


ORIGIN  AND  DURATION  OF  PETROLEUM.       273 

Since  the  above  was  written — in  February,  1880 — I  have 
tested  this  luminous  paint  (Balmain's  patent).  Practically, 
I  find  it  unsatisfactory.  In  the  first  place,  its  endurance  is 
far  shorter  than  is  stated.  It  begins  to  fade  almost  imme- 
diately the  light  is  withdrawn,  and  in  the  course  of  an  hour 
or  two  it  is,  for  all  practical  use— -though  not  absolutely — 
extinguished.  Besides  this  it  emits  a  very  unpleasant  odor 
painfully  resembling  sewage  and  sulphureted  hydrogen. 
This  is  doubtless  due  to  the  sulphur  compound,  but  is,  I 
have  no  doubt,  quite  harmless  in  spite  of  its  suggestions. 


THE  ORIGIN  AND  PROBABLE  DURATION  OF 
PETROLEUM. 

IN  spite  of  the  enormous  quantities  of  mineral  oil  that 
are  continuously  drawn  from  the  earth,  and  the  many  places 
from  which  it  may  thus  be  drawn,  geologists  are  still  puz- 
zled to  account  for  it.  If  it  were  commonly  associated  with 
coal  the  problem  of  its  origin  would  be  solved  at  once.  We 
should  then  be  satisfied  that  natural  mineral  oil  is  produced 
in  the  same  manner  as  the  artificial  product,  i.e.,  by  the 
heating  and  consequent  distillation  of  certain  kinds  of  coal 
or  of  bituminous  shales ;  but,  as  a  matter  of  fact,  -it  is  but 
rarely  that  petroleum  is  found  in  the  midst  of  coal  seams, 
though  it  is  sometimes  so  found. 

I  visited,  some  years  ago,  a  coal-mine  in  Shropshire, 
known  as  "  the  tarry  pit,"  thus  named  on  account  of  the 
large  quantity  of  crude  mineral  oil  of  a  rather  coarse  quality 
that  exuded  from  the  strata  pierced  by  the  shaft.  It  ran 
down  the  sides  of  the  shaft,  filled  the  "sumph"  (i.e.,  the 
well  at  the  bottom  of  the  shaft  in  which  the  water  draining 
from  the  mine  should  accumulate  for  pumping),  and  an- 
noyed the  colliers  so  seriously  that  they  refused  to  work  in 
the  mine  unless  the  nuisance  were  abolished.  It  was  abol- 
ished by  "  tubbing"  the  shaft  with  an  oil-proof  lining  built 
round  that  part  from  which  the  oil  issued.  The  "  tar"  as 
the  crude  oil  was  called,  was  then  pumped  out  of  the  sumph, 


274  SCIENCE  IN  SHORT  CHAPTERS. 

and  formed  a  pool  which  has  since  been  filled  up  by  the 
debris  of  the  ordinary  mine  workings. 

A  publican  in  the  'Black  Country  of  South  Staffordshire 
discovered  an  issue  of  inflammable  vapor  in  his  cellar,  col- 
lected it  by  thrusting  a  pipe  into  the  ground,  and  used  it 
for  lighting  and  warming  purposes,  as  well  as  an  attraction 
to  customers. 

These  and  other  cases  that  might  be  cited,  although  ex- 
ceptional, are  of  some  value  in  helping  us  to  form  a  simple 
and  rational  theory  of  the  origin  of  this  important  natural 
product.  They  prove  that  mineral  oil  may  be  produced  in 
connection  with  coal  seams  and  apparently  from  the  coal 
itself.  A  sound  theory  of  the  origin  of  petroleum  is  of 
practical  as  well  as  theoretical  value,  inasmuch  as  the  very 
practical  question  of  the  probable  permanency  of  supply 
depends  entirely  on  the  nature  of  the  origin  of  that  supply. 
Some  very  odd  theories  have  been  put  forth,  especially  m 
America. 

Seeing  that  petroleum  is  commonly  found  associated  with 
sandstone  and  limestone,  especially  in  cavities  of  the  latter, 
it  has  been  supposed  that  these  minerals  somehow  produce 
it.  Turning  back  to  the  Grocer  for  April  18,  1872.  I 
find  some  speculations  of  this  kind  quoted  from  the  Pe- 
troleum Monthly  The  writer  sets  aside  altogether,  as  an 
antiquated  and  exploded  fallacy,  the  idea  that  petroleum 
is  produced  from  coal,  and  maintains  "that  petroleum  is 
mainly  produced  from,  or  generated  through,  limestone," 
and  argues  that  the  generation  of  petroleum  by  such  rocks 
is  a  continuous  process,  from  the  fact  that  exhausted  Avells 
have  recovered  after  being  abandoned,  his  explanation  being 
"  that  the  formerly  abandoned  territory  was  given  up  be- 
cause the  machinery  for  extracting  petroleum  from  the  earth 
exceeded  in  its  power  of  exhausting  the  fluid  the  generative 
powers  by  which  it  is  produced  ;"  these  generative  powers 
somehow  residing  in  the  limestone  and  sandstone,  but  how 
is  not  specified. 

Some  writers  have,  however,  gone  a  little  further  toward 
answering  the  question  of  how  limestone  may  generate 
petroleum.  They  have  pointed  to  the  fossilized  remains  of 
animals,  their  shells,  etc..  existing  in  the  limestone,  and 


ORIGIN  AND  DURATION  OF  PETROLEUM.       275 

have  supposed  that  the  animal  matter  has  been  distilled, 
and  has  thus  formed  the  oil. 

If  such  a  process  could  be  imitated  artificially  by  distill- 
ing some  of  the  later  deposits  of  similar  fossil  character 
this  theory  would  have  a  better  basis,  or  even  if  a  collection 
of  oysters,  mussels,  or  any  other  animal  matters  could  by 
distillation  be  shown  to  produce  an  oil  similar  to  petro- 
leum. 

The  contrary  is  the  case.  We  may  obtain  oil  from  such 
material,  but  it  is  utterly  different  from  any  kind  of  min- 
eral oil,  while,  on  the  other  hand,  by  distilling  natural  bi- 
tuminous shales,  or  canuel  coal,  or  peat,  we  obtain  a  crude 
oil  almost  identical  with  natural  petroleum,  and  the  little 
difference  between  the  two  is  perfectly  accounted  for  by  the 
greater  rapidity  of  our  methods  of  distillation  as  compared 
with  the  slow  natural  process.  "We  may  go  on  approximat- 
ing more  and  more  nearly  to  the  natural  petroleum  by  dis- 
tilling more  and  more  slowly.  As  it  is,  the  refined  products 
of  the  natural  and  artificial  oil  which  is  commercially  dis- 
tilled in  Scotland,  are  scarcely  distinguishable— some  of 
them  are  not  at  all  distinguishable — the  solid  paraffin,  for 
example.  I  now  offer  my  own  theory  of  the  origin  of  oil 
springs. 

To  render  this  the  more  intelligible,  let  us  first  consider 
the  origin  of  ordinary  water  springs.  St.  Winifred's  Well, 
at  Holywell,  in  Flintshire,  maybe  taken  as  an  example,  not 
merely  on  account  of  its  magnitude,  but  because  it  is  quite 
typical,  and  is  connected  with  limestone  and  sandstone  in 
about  the  Fame  manner  as  are  the  petroleum  wells  of 
Pennsylvania. 

Here  we  have  a  wondrous  uprush  of  water  just  between 
the  sandstone  and  mountain  limestone  rocks,  which  amounts 
to  above  twenty  tons  per  minute,  and  flows  down  to  the 
Dee,  a  small  river  turning  several  water-mills.  It  is  cer- 
tain that  all  this  water  is  not  generated  either  by  the  lime- 
stone or  the  sandstone  from  which  it  issues,  nor  can  it  be 
all  "generated  "  on  the  spot.  The  true  explanation  of  its 
origin  is  simple  enough. 

The  mountain  limestone  underlies  the  coal  measures  and 
crops  up  obliquely  at  Holywell;  against  this  oblique  subter- 


276  SCIENCE  IN  SHORT  CHAPTERS. 

ranean  wall  of  compact  rock  impermeable  to  water,  abuts  a 
great  face  of  down-sloping  strata  of  porous  sandstone  and 
porous  shales.  These  porous  rocks  receive  the  rain  which 
falls  on  the  slopes  of  the  Hope  Mountain  and  other  hills 
which  they  form;  this  water  sinks  into  the  millstone  grit 
of  these  hills  and  percolates  downwards  until  it  reaches  the 
limestone  barrier,  into  which  it  cannot  penetrate. 

It  here  accumulates  as  a  subterranean  reservoir  which 
finds  an  outlet  at  a  convenient  natural  fissure,  and,  as  the 
percolation  is  continuous,  the  spring  is  a  constant  one. 
Some  of  the  water  travels  many  miles  underground  before 
it  thus  escapes.  Hundreds  of  other  smaller  instances  might 
be  quoted,  the  above  being  the  common  history  of  springs 
which  start  up  whenever  the  underground  waters  that  flow 
through  porous  rocks  or  soil  meet  with  compact  rocks  or 
impermeable  clay,  and  thus,  being  able  to  proceed  no  fur- 
ther downwards,  accumulate  and  produce  an  overflow  which 
we  call  a  "spring." 

If  water  can  thus  travel  underground,  why  not  oil? 

Although  the  oil  springs  or  oil  wells  are  not  immediately 
above  or  below  coal  seams,  they  are  all  within  "  measura- 
ble distance"  of  great  coal  formations — the  oil  territory  of 
Pennsylvania  is,  in  fact,  surrounded  by  coal,  some  of  it  an- 
thracite, which  is  really  a  coke,  such  as  would  be  produced 
if  we  artificially  distilled  the  hydrocarbons  from  coal,  and 
then  compressed  the  residue,  as  the  anthracite  has  certainly 
been  pressed  by  the  strata  resting  upon  it. 

The  rocks  in  immediate  contact  and  proximity  to  coal 
seams — "  the  coal  measures,"  as  they  are  called — are  mostly 
porous,  some  of  them  very  porous,  and  thus  if  at  any  period 
of  the  earth's  long  history  a  seam  of  coal  became  heated,  as 
we  know  so  many  strata  are,  and  have  been  heated,  a 
mineral  oil  would  certainly  be  formed,  would  first  permeate 
the  porous  rocks  as  vapor,  then  be  condensed  and 'make  its 
way  through  them,  following  their  "dip"  or  inclination 
until  it  reached  a  barrier  such  as  the  limestone  forms. 

It  would  thus  in  after-ages  be  found,  not  among  the  coal 
where  it  was  formed,  but  at  the  limestone  or  other  imper- 
meable rock  by  whicn  its  further  percolation  was  arrested. 

This  is  just  where  it  actually  is  found. 


ORIGIN  AND  DURATION  OF  PETROLEUM.       277 

Limestone,  although  not  porous  like  shales  and  sand- 
stones, is  specially  well  adapted  for  storing  large  subter- 
ranean accumulations,  on  account  of  the  grent  cavities  to 
which  it  is  liable.  Nearly  all  the  caverns  in  this  country, 
in  Ireland  where  they  abound,  in  America,  and  other  parts 
of  the  world,  are  in  limestone  rocks ;  they  are  especially 
abundant  in  the  "  carboniferous  limestone"  which  underlies 
the  coal  measures,  and  this  is  explained  by  the  fact  that  lime- 
stone may  be  dissolved  by  rain-water  that  has  oozed  through 
vegetable  soil  or  has  soaked  fallen  leaves  or  other  vegetable 
matter,  and  thereby  become  saturated  with  carbonic  acid. 

Where  the  petroleum  finds  a  crevice  leading  to  such 
cavities  it  must  creep  through  it  and  fill  the  space,  thereby 
forming  one  of  the  underground  reservoirs  supplying  those 
pumping  wells  that  have  yielded  such  abundance  for  a  while 
and  then  become  dry.  But  if  this  theory  is  correct  it  does 
not  follow  that  the  drying  of  such  a  well  proves  a  final 
stoppage  of  the  supply,  for  if  the  cavity  and  crevice  are  left, 
more  oil  may  ooze  into  the  crevice  and  flow  into  the  cavity, 
and  this  may  continue  again  and  again  throughout  the 
whole  oil  district  so  long  as  the  surrounding  feeders  of  per- 
meable strata  continue  saturated,  or  nearly  so.  The  mag- 
nitude of  these  feeding  grounds  may  far  exceed  that  of  the 
district  wherein  the  springs  occur,  or  where  profitable  wells 
may  be  sunk,  seeing  that  the  localizing  of  profitable  supply 
depends  mainly  on  the  stoppage  of  further  oozing  away  by 
the  action  of  the  impermeable  barrier. 

A  well  sunk  into  the  oozing  strata  itself  would  receive  a 
very  small  quantity,  only  that  which,  in  the  course  of  its 
passage  came  upon  the  well  sides,  while  at  the  junction  be- 
tween the  permeable  and  the  impermeable  rocks  the  accu- 
mulation may  include  all  that  reached  the  whole  surface  of 
such  junction  or  contact — many  square  miles. 

To  test  this  theory  thoroughly  it  would  be  necessary  to 
make  borings,  not  merely  at  the  wells,  but  in  their  neigh- 
borhood, where  the  porous  rocks  dip  towards  the  limestone, 
and  to  bring  up  sample  cores  of  these  porous  rocks,  and 
carefully  examine  them.  Dr.  Sterry  Hunt  has  done  this  in 
the  oil-yielding  limestone  rocks  of  Chicago,  but  not  in  those 
of  the  nearest  coal-measures. 


278  SCIENCE  IN  SHORT  CHAPTERS. 

As  the  oil  industry  of  America  is  of  such  great  national 
importance,  an  investigation  of  this  kind  is  worthy  of  the 
energies  of  the  American  Government  geologists.  It  would 
throw  much  light  on  the  whole  subject,  and  supply  data 
from  which  the  probable  duration  of  the  oil  supply  might 
be  approximately  calculated. 

Such  an  investigation  might  even  do  more  than  this.  By 
proving  the  geological  conditions  upon  which  depend  the 
production  of  petroleum  springs,  new  sources  may  be  dis- 
covered, just  as  new  coal-seams  have  been  discovered,  in 
accordance  with  geological  prediction,  or  as  the  practical 
discovery  of  the  Austrian  gold-fields  was  so  long  preceded 
by  Sir  Roderick  Murchison's  theoretical  announcement  of 
their  probable  existence. 

When  the  "kerosene  wells"  were  first  struck,  the  specu- 
lations concerning  their  probable  permanency  were  wild  and 
various.  Some  maintained  that  it  was  but  a  spurt,  a  freak 
of  nature  limited  to  a  narrow  locality,  and  would  soon  be 
over ;  others  asserted  forthwith  that  American  oil,  like 
everything  else  American,  was  boundless.  Neither  had  any 
grounds  for  their  assertions,  and  therefore  made  them  with 
the  usual  boldness  of  mere  dogmatism. 

Then  came  a  period  of  scare,  started  by  the  fact  that 
w\3lls  which  at  first  spouted  an  inflammable  mixture  of  oil 
and  vapor  high  into  the  air  soon  became  quiescent,  and 
from  "spouting  wells"  became  "flowing  wells,"  merely 
pouring  out  on  the  surface  a  small  stream  at  first,  which 
gradually  declined  to  a  dribble,  and  finally  ceased  to  flow  at 
all.  Even  those  that  started  modestly  as  flowing  wells  did 
the  latter,  and  thus  appeared  to  become  exhausted. 

This  exhaustion,  however,  was  only  apparent,  as  was 
proved  by  the  application  of  pumps,  which  drew  up  from 
wells,  that  had  ceased  either  to  spout  or  flow,  large  and 
apparently  undiminishing  quantities  of  crude  oil. 

Further  observation  and  thought  revealed  the  cause  of 
these  changes.  It  became  understood  that  the  spouting  was 
due  to  the  tapping  of  a  rock-cavity  containing  oil  of  such 
varying  densities  and  volatility  that  some  of  it  flew  out  as  a 
vapor,  or  boiled  at  the  mean  temperature  of  the  air  of  the 
country  or  that  of  the  surrounding  rocks.  Such  being  the 


ORIGIN  AND  DURATION  OF  PETROLEUM.       279 

case,  the  cavity  was  filled  with  high-pressure  oil- vapor 
straining  to  escape.  If  the  bore-hole  tapped  the  crown  or 
highest  curve  of  the  roof  of  such  an  oil-cavern,  it  opened 
directly  into  the  vapor  there  accumulated,  and  the  vapor 
itself  rushed  out  with  such  force  that  a  pillar  of  fire  was 
raised  in  the  air  if  a  light  came  within  some  yards  of  the 
orifice.  We  are  told  of  heavy  iron  boring-rods  that  were 
shot  up  to  wondrous  heights — and  we  may  believe  these 
stories  if  we  please. 

If  the  bore-hole  struck  lower  down,  somewhere  on  the 
sloping  sides  or  in  the  shallow  lower  branches  of  the  oil- 
cavern,  it  dipped  at  once  into  liquid  oil,  and  this  oil,  being 
pressed  by  the  elastic  vapor  of  the  upper  part,  was  forced 
up  as  a  jet  of  spouting  oil. 

In  either  case  these  violent  proceedings  soon  came  to 
an  end,  for  as  the  vapor  or  oil  poured  out,  the  space  above 
the  oil-level  where  the  vapor  had  been  confined  was 
increased,  and  its  pressure  diminished,  till  at  last  it  barely 
sufficed  to  raise  the  oil  to  the  surface,  afld  afterwards  failed 
to  do  that. 

It  is  quite  clear  from  this  that  the  supplies  are  not 
"  inexhaustible."  The  quantity  of  vapor  having  been 
limited,  there  must  also  be  a  limit  to  the  quantity  of  oil 
giving  off  this  vapor;  the  space  in  the  oil-cavern  occupied 
by  this  vapor  having  been  limited,  there  must  be  a  limit  to 
the  space  occupied  by  the  oil.  The  quantity  of  oil  may  be 
ten  times,  a  hundred  times,  a  thousand  times,or  ten  thousand 
times,  greater  than  that  of  the  vapor,  but  in  either  or  any 
case  it  must  come  to  an  end  at  last,  sooner  later. 

If  there  were  but  a  few  wells  here  and  there,  as  at  other 
similar  places,  such  as  Rangoon,  the  Persian  oil-wells,  etc., 
the  pumping  might  continue  for  centuries  and  centuries; 
bnt  this  is  not  the  case  in  America.  The  final  boundaries 
of  the  oil-bearing  strata  may  not  yet  have  been  reached; 
but  so  far  as  they  are  known  they  are  riddled  through  and 
through,  and  pumped  in  every  direction,  so  that  the  end 
must  come  at  last,  though  with  our  present  knowledge  we 
cannot  say  when. 

We  can,  however,  say  how  it  must  come.  It  will  not  be 
a  sudden  stoppage,  but  a  gradual  exhaustion  indicated  by 


280  SCIENCE  IN  SHORT  CHAPTERS. 

progressive  diminution  of  supply.  We  shall  not  be  suddenly 
deprived  of  this  important  source  of  light  and  cheerfulness; 
but  we  may  at  any  time  begin  to  feel  the  pinch  of  scarcity 
and  consequent  rise  of  price.  This  rise  of  price  will  check 
the  demand,  and  bring  forth  other  supplies  from  sources 
that  now  cannot  be  profitably  worked  on  account  of  the 
cheapness  of  American  petroleum. 

Many  of  the  countries  now  largely  supplied  from  America 
have  oil-springs  of  their  own,  which  a  rise  of  price  will 
speedily  bring  into  paying  operation. 

We  have  nothing  to  fear.  The  fact  that  in  spite  of  the 
ruinous  prices  that  have  recently  prevailed  the  Scotch  oil- 
makers  continue  to  exist  at  all,  shows  us  what  they  may  do 
with  a  rise  of  even  a  few  pence  per  gallon.  The  thickness 
and  area  of  the  dark  shales  from  which  their  oil  is  distilled 
are  so  great  that  their  exhaustion  is  very  far  remote  indeed. 
The  Americans  have  similar  shales  to  fall  back  upon  when 
the  spontaneous  product  ceases  to  flow,  but  they  are  quite 
incapable  of  competing  with  us  at  home  on  equal  terms — 
that  is, when  both  have  to  'obtain  the  oil  as  a  manufactured 
product  of  artificial  distillation. 

If  anything  like  moderation  were  possible  in  America, 
the  first  indications  of  scarcity  would  be  followed  by  some 
economy  in  working;  but  this  is  not  to  be  anticipated.  It 
is  more  likely  that  the  first  rise  of  prices  will  attract  addi- 
tional speculatidn,  and  the  sinking  of  more  wells  in  the  hope 
of  large  profits,  and  this  of  course  will  shorten  the  period 
of  gradual  exhaustion,  the  commencement  of  which  may, 
for  aught  we  know,  be  very  near  at  hand,  especially  if  the 
new  projects  for  using  petroleum  as  furnace  fuel  under 
steam  boilers,  and  for  the  smelting,  puddling,  and  founding 
of  iron  and  other  metals,  are  carried  out  as  they  may  be  so 
easily  at  present  prices,  and  with  the  aid  of  pipe-lines  to 
carry  the  crude  or  refined  oil  from  the  wells  to  any  part  of 
the  great  American  continent  where  it  may  be  required  in 
large  quantities. 

The  old  story  of  the  goose  that  laid  the  golden  eggs  seems 
to  be  in  course  of  repetition  in  Transatlantic  Petrolia. 

Since  the  above  was  written  I  have  received  from  Dr. 


THE  ORIGIN  OF  SOAP.  281 

Sterry  Hunt  a  copy  of  his  interesting  "  Chemical  and  Geo- 
logical Essays,"  in  one  of  which  he  expoundfa  theory  of  the 
origin  of  petroleum.  He  states  that  it  appears  to  him  "  that 
the  petroleum,  or  rather  the  materials  from  which  it  has 
been  formed,  existed  in  the  limestone  rocks  from  the  time 
of  their  first  deposition,"  and  "that  petroleum  and  similar 
bitumens  have  resulted  from  a  peculiar  transformation  of 
vegetable  matters,  or  in  some  cases  of  animal  tissues 
analogous  to  these  in  composition."  • 

The  objections  on  page  275  apply  to  the  animal  tissues 
of  this  theory,  and  as  regards  the  vegetable  matter  I  think 
it  fails  from  the  want  of  anything  like  an  adequate  supply 
in  these  limestone  rocks. 


THE  ORIGIN  OF  SOAP. 

A  filSTOEY  of  soap  would  be  very  interesting.  Who  in- 
vented it?  When  and  where  did  it  first  come  into  common 
use?  How  did  our  remote  ancestors  wash  themselves  before 
soap  was  invented?  These  are  historical  questions  that 
naturally  arise  at  first  contemplation  of  the  subject;  but,  as 
far  as  we  are  aware,  historians  have  failed  to  answer  them. 
We  read  a  great  deal  in  ancient  histories  about  anointing 
with  oil  and  the  use  of  various  cosmetics  for  the  skin,  but 
nothing  about  soap. 

These  ancients  must  have  been  very  greasy  people,  and 
I  suspect  that  they  washed  themselves  pretty  nearly  in  the 
same  way  as  modern  engine  drivers  clean  their  fingers,  by 
wiping  off  the  oil  with  a  bit  of  cotton-waste. 

We  are  taught  to  believe  that  the  ancient  Romans 
wrapped  themselves  round  with  togas  of  ample  dimensions, 
and  that  these  togas  were  white.  Now,  such  togas,  after 
encasing  such  anointed  oily  skins,  must  have  become  very 
greasy.  How  did  the  Roman  laundresses  or  launders— 
historians  do  not  indicate  their  sex — remove  this  grease? 
Historians  are  also  silent  on  this  subject. 

A  great  many  curious  things  were  found  buried  under 


282  SCIENCE  IN  SHORT  CHAPTERS. 

the  cinders  of  Vesuvius  in  Pompeii,  and  sealed  up  in  the 
lava  that  flowed  over  Herculaneum.  Bread,  Avine,  fruits, 
and  other  domestic  articles,  including  several  luxuries  of 
the  toilet,  such  as  pomades  or  pomade-pots,  and  rouge 
for  painting  ladies'  faces,  but  no  soap  for  washing  them. 
In  the  British  Museum  is  a  large  variety  of  household 
requirements  found  in  the  pyramids  of  Egypt,  but  there  is 
no  soap,  and  we  have  not  heard  of  any  having  been  dis- 
covered there. 

Finding  no  traces  of  soap  among  the  Romans,  Greeks,  or 
Egyptians,  we  need  not  go  back  to  the  pre-historic  ''cave 
men,"  whose  flint  and  bone  implements  were  found  embed- 
ded side  by  side  with  the  remains  of  the  mammoth  bear  and 
hyena  in  such  caverns  as  that  at  Torquay,  where  Mr.  Pen- 
gelly  has,  during  the  last  eighteen  years,  so  industriously 
explored. 

All  our  knowledge,  and  that  still  larger  quantity,  our 
ignorance,  of  the  habits  of  antique  savages,  indicate  that 
solid  soap,  such  as  we  commonly  use,  is  a  comparatively 
modern  luxury;  but  it  does  not  follow  that  they  had  no 
substitute.  To  learn  what  that  substitute  may  probably 
have  been  we  may  observe  the  habits  of  modern  savages,  or 
primitive  people  at  home  and  abroad. 

This  will  teach  us  that  clay,  especially  where  it  is  found 
having  some  of  the  unctuous  properties  of  fuller's-earth,  is 
freely  used  for  lavatory  purposes,  and  was  probably  used  by 
the  Romans,  who  were  by  no  means  remarkable  for  any- 
thing approaching  to  true  refinement.  They  were  essen- 
tially a  nasty  people,  the  habits  of  the  poor  being  "cheap 
and  nasty;"  of  the  rich,  luxurious  and  nasty.  The  Roman 
nobleman  did  not  sit  down  to  dinner,  but  sprawled  with 
his  face  downwards,  and  took  his  food  as  modern  swine  take 
theirs.  At  grand  banquets,  after  gorging  to  repletion,  he 
tickled  his  throat  in  order  to  vomit  and  make  room  for 
more.  He  took  baths  occasionally,  and  was  probably  scoured 
and  shampooed  as  well  as  oiled,  but  it  is  doubtful  whether 
he  performed  any  intermediate  domestic  ablutions  worth 
naming. 

A  refinement  upon  washing  with  clay  is  to  be  found  in 
the  practice  once  common  in  England,  and.still  largely  used 


THE  ORIGIN  OF  SOAP.  288 

wliere  wood  fires  prevail.  It  is  the  old-fashioned  practice 
of  pouring  water  on  the  wood  ashes,  and  using  the  "lees" 
thus  obtained.  These  lees  are  a  solution  of  alkaline  car- 
bonate of  potash  the  modern  name  of  potash  being  derived 
from  the  fact  that  it  was  original!}*  obtained  from  the  ashes 
under  the  pot.  In  like  manner  soda  was  obtained  from  the 
ashes  of  seaweeds  and  of  the  plants  that  grow  near  the  sea- 
shore, such  as  the  salsover  soda,  etc. 

The  pot-ashes  or  pearl-ashes  being  so  universal  as  a.  do- 
mestic bi-product,  it  was  but  natural  that  they  should  be 
commonly  used,  especially  for  the  washing  of  greasy  clothes, 
as  they  are  to  the  present  day.  Upon  these  facts  we  may 
build  up  a  theory. of  the  origin  of  soap. 

It  is  a  compound  of  oil  or  fat  with  soda  or  potash,  and 
would  be  formed  accidentally  if  the  fat  on  the  surface  of  the 
pot  should  boil  over  and  fall  into  the  ashes  under  tSe  pot. 
The  solution  of  such  a  mixture  if  boiled  down  would  give 
us  soft  soap. 

If  oil  or  fat  became  mixed  with  the  ashes  of  soda  plants, 
it  would  produce  hard  soap.  Suqj^  a  mixture  would  most 
easily  be  formed  accidentally  in  regions  where  the  olive 
flourishes  near  the  coast,  as  in  Italy  and  Spain  for  example, 
and  this  mixture  would  be  Castile  soap,  which  is  still  largely 
made  by  combining  refuse  or  inferior  olive  oil  with  the  soda 
obtained  from  the  ashes  of  seaweed. 

The  primitive  soap-maker  would,  however,  encounter  one 
difficulty — that  arising  from  the  fact  that  the  potash  or  soda 
obtained  by  simple  burning  of  the  wood  or  seaweed  is  more 
or  less  combined  with  carbonic  acid,  instead  of  being  all  in 
the  caustic  state  which  is  required  for  effective  soap-making. 
The  modern  soap-maker  removes  this  carbonic  acid  by 
means  of  caustic  lime,  which  takes  it  away  from  the  car- 
bonate of  soda  or  carbonate  of  potash  by  simple  exchange — 
i.e.,  caustic  lime  plus  carbonate  of  soda  becoming  caustic 
soda  plus  carbonate  of  lime,  or  carbonate  of  potash  plus 
caustic  lime  becoming  caustic  potash  plus  carbonate  of  lime. 

How  the  possibility  of  making  this  exchange  became 
known  to  the  primitive  soap-maker,  or  whether  he  knew  it 
at  all,  remains  a  mystery,  but  certain  it  is  that  it  was  prac- 
tically used  long  before  the  chemistry  of  the  action  was  at 


284  SCIENCE  IN  SHORT  CHAPTERS. 

all  understood.  It  is  very  probable  that  the  old  alchemists 
had  a  hand  in  this. 

In  their  search  for  the  philosopher's  stone,  the  elixir  of 
life,  or  drinkable  gold,  and  for  the  universal  solvent,  they 
mixed  together  everything  that  came  to  hand,  they  boiled 
everything  that  was  boilable,  distilled  everything  that  was 
volatile,  burnt  everything  that  was  combustible,  and  tor- 
tured all  their  "simples"  and  their  mixtures  by  every  con- 
ceivable device,  thereby  stumbling  upon  many  curious,  many 
wonderful,  and  many  useful  results.  Some  of  them  were 
not  altogether  visionary — were,  in  fact,  very  practical,  quite 
capable  of  understanding  the  action  of  caustic  lime  on  car- 
bonate of  soda,  and  of  turning  it  to  profitable  account. 

It  is  not,  however,  absolutely  necessary  to  use  the  lime, 
as  the  soda  plants  when  carefully  burned  in  pits  dug  in  the 
sand  ©f  the  sea-shore  may  contain  but  little  carbonic  acid  if 
the  ash  is  fluxed  into  a  hard  cake  like  that  now  commonly 
produced,  and  sold  as  "soda  ash."  This  contains  from 
three  to  thirty  per  cent  of  carbonate,  and  thus  some 
samples  are  nearly  caustic,  without  the  aid  of  lime. 

As  cleanliness  is  the^Pundamental  basis  of  all  true  physi- 
cal refinement,  it  has  been  proposed  to  estimate  the  pro- 
gress of  civilization  by  the  consumption  of  soap,  the  relative 
civilization  of  given  communities  being  numerically  meas- 
ured by  the  following  operation  in  simple  arithmetic: — Di- 
vide the  total  quantity  of  soap  consumed  in  a  given  time 
by  the  total  population  consuming  it,  and  the  quotient  ex- 
presses the  civilization  of  that  community.* 

The  allusion  made  by  Lord  Beaconsfield,  at  the  Lord 
Mayor's  dinner  in  1879,  to  the  prosperity  of  our  chemical 
manufactures  was  a  subject  of  merriment  to  some  critics, 
who  are  probably  ignorant  of  the  fact  that  soap-making  is  a 


*  The  scientific  pedant  of  the  Middle  Ages  displayed  his  profundity 
by  continually  quoting  Aristotle  and  other  "ancients."  His  modern 
successor  does  the  like  by  decorating  his  pages  with  displays  of  alge- 
braical formulae.  In  order  to  secure  the  proper  respect  of  my  readers 
I  here  repeat  the  equation  that  I  enunciated  many  years  ago,  "c=s" 

where  e  stands  for  civilization,  s  for  the  quantity  of  soap  consumed 
per  annum,  and  p  the  population  of  a  given  community. 


OILING   THE  WAVES.  285 

chemical  manufacture,  and  that  it  involves  many  other 
chemical  manufactures,  some  of  them,  in  their  present  state, 
the  results  of  the  highest  refinements  of  modern  chemical 
science. 

While  the  fishers  of  the  Hebrides  and  the  peasants  on  the 
shores  of  the  Mediterranean  are  still  obtaining  soda  by 
burning  seaweed  as  they  did  of  old,  our  chemical  manufac- 
turers are  importing  sulphur  from  Sicily  and  Iceland, 
pyrites  from  all  quarters,  nitrate  of  soda  from  Peru  and  the 
East  Indies,  for  the  manufacture  of  sulphuric  acid,  by  the 
'aid  of  which  they  now  make  enormous  quantities  of  caustic 
soda  from  the  material  extracted  from  the  salt  mines  of 
Cheshire  and  Droitwich.  These  sulphuric  acid  works  and 
these  soda  works  are  among  the  most  prosperous  and  rapidly 
growing  of  our  manufacturing  industries,  and  their  chief 
function  is  that  of  ministering  to  soap-making,  in  which 
Britain  is  now  competing  triumphantly  with  all  the  world. 

By  simply  considering  how  much  is  expended  annually 
for  soap  in  every  decent  household,  and  adding  to  this  the 
quantity  consumed  in  laundries  and  by  our  woolen  and 
cotton  manufacturers,  a  large  sum  total  is  displayed.  For- 
merly, we  imported  much  of  the  soap  we  used  at  home; 
now,  in  spite  of  our  greatly  magnified  consumption,  we 
supply  ourselves  with  all  but  a  few  special  kinds,  and  ex- 
port very  large  and  continually  increasing  quantities  to  all 
parts  of  the  world;  and  if  the  arithmetical  rule  given  above 
is  sound,  the  demand  must  steadily  increase  as  civilization 
advances. 


OILING  THE  WAVES. 

THE  recent  gales  have  shown  that  if  "  Britannia  rules 
the  waves"  her  subjects  are  very  turbulent  and  costly. 
Our  shipping  interests  are  now  of  enormous  magnitude, 
and  they  are  growing  year  by  year.  We  are,  in  fact,  be- 
coming the  world's  carriers  on  the  ocean,  and  are  thus  rul- 
ing the  waves  in  a  far  better  sense  than  in  the  old  one. 
Our  present  mercantile  rule  adds  to  the  wealth  of  our 


286  SCIENCE  IN  SHORT  CHAPTERS* 

neighbors  instead  of  destroying  it,  as  under  the  old  war- 
like rule. 

Everything  concerning  these  waves  is  thus  of  great  na- 
tional interest,  the  loss  of  life  and  sacrifice  of  wealth  by 
marine  casualties  being  so  great.  Some  curious  old  stories 
are  extant,  describing  the  exploits  of  ancient  mariners  in 
stilling  the  waves  by  pouring  oil  upon  them.  Both  Plu- 
tarch and  Pliny  speak  of  it  as  a  regular  practice.  Much 
later  than  this,  in  a  letter  dated  Batavia,  January  5,  1770, 
written  by  M.  Tengragel,  and  addressed  to  Count  Ben- 
tinck,  the  following  passage  occurs: — "  Near  the  islands 
Paul  and  Amsterdam  we  met  with  a  storm,  which  had 
nothing  particular  in  it  worthy  of  being  communicated  to 
you,  except  that  the  captain  found  himself  obliged,  for 
greater  safety  in  wearing  the  ship,  to  pour  oil  into  the  sea 
to  prevent  the  waves  breaking  over  her,  which  had  an  ex- 
cellent effect,  and  succeeded  in  preserving  -us.  As  he 
poured  out  but  a  little  at  a  time,  the  East  India  Company 
owes,  perhaps,  its  ship  to  only  six  demi-aumes  of  olive  oil. 
I  was  present  on  deck  when  this  was  done,  and  should  not 
have  mentioned  this  circumstance  to  you,  but  that  we  have 
found  people  here  so  prejudiced  against  the  experiment  as 
to,  make  it  necessary  for  the  officers  on  board  and  myself  to 
give  a  certificate  of  the  truth  on  this  head,  of  which  we 
made  no  difficulty." 

The  idea  was  regarded  with  similar  prejudice  by  scientific 
men  until  Benjamin  Franklin  had  his  attention  called  to 
it,  as  he  thus  narrates: — "  In  1757,  being  at  sea  in  a  fleet 
of  ninety-six  sail,  bound  for  Louisbourg,  I  observed  the 
wakes  of  two  of  the  ships  to  be  remarkably  smooth,  Avhile 
all  the  others  were  ruffled  by  the  wind,  which  blew  fresh. 
Being  puzzled  with  the  differing  appearance,  I  at  last 
pointed  it  out  to  the  captain,  and  asked  him  the  meaning 
of  it.  'The  cooks,'  said  he,  '  have,  I  suppose,  been  just 
emptying  their  greasy  water  through  the  scuppers,  which 
has  greased  the  sides  of  the  ships  a  little.'  And  this  an- 
swer he  gave  me  with  an  air  of  some  little  contempt,  as  to 
a  person  ignorant  of  what  everybody  else  knew.  In  my 
own  mind,  I  first  slighted  the  solution,  though  I  was  not 
able  to  think  of  another." 


OIL1AG    THE   WAVES.  287 

Franklin  was  not  a  man  to  remain  prejudiced;  he  ac- 
cordingly investigated  the  subject,  aft.d  the  results  of  his 
experiments,  made  upon  a  pond  on  Clapham  Common, 
were  communicated  to  the  Koyal  Society.  He  states  that 
after  dropping  a  little  oil  on  the  water,  "  I  saw  it  spread 
itself  with  surprising  swiftness  upon  the  surface,  but  the 
effect  of  smoothing  the  waves  was  not  produced;  for  I  had 
applied  it  first  upon  the  leeward  side  of  the  pond,  where 
the  waves  were  largest,  and  the  wind  drove  my  oil  back 
upon  the  shore.  I  then  went  to  the  windward  side,  where 
they  began  to  form;  and  there  the  oil,  though  not  more 
than  a  teaspoonful,  produced  an  instant  calm  over  a  space 
several  yards  square,  which  spread  amazingly,  and  extended 
itself  gradually  till  it  reached  the  lee  side,  making  all  that 
quarter  of  the  pond  (perhaps  half  an  acre)  as  smooth  as  a 
looking-glass." 

Franklin  made  further  experiments  at  the  entrance  of 
Portsmouth  Harbor,  opposite  the  Haslar  Hospital,  in  com- 
pany with  Sir  Joseph  Banks,  Dr.  Blagden,  and  Dr.  Solan- 
der.  In  these  experiments  the  waves  were  not  destroyed, 
but  were  converted  into  gentle  swelling  undulations  with 
smooth  surfaces.  Thus  it  appeared  that  the  oil  destroys 
small  waves,  but  not  large  billows. 

Franklin's  explanation  is,  "  that  the  wind  blowing  over 
water  covered  with  a  film  of  oil  cannot  easily  catch  upon  it, 
so  as  to  raise  the  first  wrinkles,  but  slides  over  it  and  leaves 
it  smooth  as  it  finds  it." 

Further  investigations  have  since  been  made  which  con- 
firm this  theory.  The  first  action  of  the  wind  in  blowing 
up  what  the  sailors  call  "  a  sea,"  is  the  production  of  a  rip- 
ple on  the  surface  of  the  water.  This  ripple  gives  the 
wind  a  strong  hold,  and  thus  larger  waves  are  formed,  but 
on  these  larger  there  are  smaller  waves,  and  on  these 
smaller  waves  still  smaller  ripples.  All  this  roughness  of 
surface  goes  on  helping  the  wind,  till  at  last  the  mightiest 
billows  are  formed,  which  then  have  an  oscillation  inde- 
pendent of  the  wind  that  formed  them.  Hence  the  oil 
cannot  at  once  subdue  the  great  waves  that  are  already 
formed,  but  may  prevent  their  formation  if  applied  in  time. 
Even  the  great  waves  are  moderated  by  the  oil  stopping 


288  SCIENCE  IN  SHORT  CHAPTERS. 

the  action  of  the  wind  which  sustains  and  augments 
them. 

.  Quite  recently,  Captain  David  Gray  made  some  experi- 
ments at  the  north  bar  of  Peterhead,  where  a  very  heavy 
surf  breaks  over  in  rough  weather.  On  a  rough  day  he 
dropped  a  bottle  full  of  oil  into  the  sea.  The  oil  floating 
out  off  the  bottle,  c&nverted  the  choppy  waves  over  a  large 
area  "  into  an  expanse  of  long  undulating  rollers,  smooth 
and  glassy,  and  so  robbed  of  all  violence  that  a  small  open 
boat  could  ride  on  them  in  safety." 

This  result  is  quite  in  accordance  with  what  we  are  told 
respecting  the  ancient  practice  of  the  fishermen  of  Lisbon, 
who  were  accustomed  to  empty  a  bottle  of  oil  into  the  sea 
when  they  found  on  their  return  to  the  river  that  there 
was  a  dangerous  surf  on  the  bar,  which  might  fill  their 
boats  in  crossing  it. 

As  regards  Peterhead,  it  is  proposed  to  lay  perforated 
pipes  across  the  mouth  of  the  harbor,  and  to  erect  tanks 
from  which  these  pipes  may  be  supplied  with  oil,  and  thus 
pour  a  continuous  and  widely  distributed  stream  into  the 
sea  in  bad  weather.  The  scheme  was  mooted  some  time 
ago,  but  I  ana  not  aware  whether  it  has  yet  been  carried 
out.  Its  success  or  failure  must  mainly  be  determined  by 
the  cost,  and  this  will  largely  depend  upon  the  kind  of  oil 
that  is  used.  A  series  of  well-conducted  experiments  upon 
the  comparative  ^ areas  protected  by  different  kinds  of  oil 
would  be  very  interesting -and  practically  useful,  for,  until 
this  has  been  ascertained,  a  proper  selection  cannot  be 
made.  How  long  will  it  last?  is  another  question. 

I  have  frequently  seen  such  tracks  as  Franklin  observed 
out  at  sea,  and  have  climbed  to  the  masthead  in  order  to 
sight  the  ship  that  produced  them,  without  seeing  any. 
Several  of  such  smooth  shining  tracks  have  been  observed 
at  the  same  time,  but  no  ship  visible,  and  this  in  places 
where  no  sail  has  been  seen  for  days  before  or  after.  The 
poet's  description  of  "  the  trackless  ocean"  is  by  no  means 
"founded  on  fact." 

The  Plymouth  Breakwater  contains  3,369,261  tons  of 
stone,  and  cost  the  British  Government  a  million  and  a  half . 
The  interest  on  this  at  4  per  cent  amounts  to  60,OOOZ.  per 


OILING   THE  WAVES.  289 

annum.  If  the  above  statements  are  reliable,  some  of  the 
wholesale  oil  merchants  who  read  this  might  contract  to 
becalm  a  considerable  area  of  the  Channel  for  a  smallef 
amount. 

Further  experiments  have  been  made  at  Peterhead  since 
the  above  was  written.  The  following  account,  from  the 
Times  of  those  made  on  February  27,  1882,  is  interesting: 

"  On  Monday  the  long-wished-for  easterly  gale  to  test 
the  experiment  of  throwing  oil  on  the  troubled  waters 
reached  Peterhead.  It  may  be  mentioned  that  the  harbor 
of  Peterhead  is  singularly  exposed,  and  with  an  east  or 
north-east  gale  is  very  dangerous  of  approach.  Mr.  Shields, 
of  Perth,  has  laid  the  oil  apparatus  to  be  used  in  quelling 
the  troubled  waters.  It  consists  of  an  iron  pipe  which  con- 
veys oil  and  extends  from  a  wooden  house  behind  the  sea- 
wall at  Eoanhead  down  through  a  natural  gullet  in  the 
rocks  about  150  yards  long  and  about  50  yards  beyond  the 
mouth  of  the  gullet  into  about  seven  fathoms  of  water;  at 
this  point  the  iron  pipe  is  joined  to  a  guttapercha  pipe, 
which  extends  across  the  harbor  entrance  outside  the  bar 
and  is  perforated  at  distances  12£  yards  apart.  Through 
the  guttapercha  pipe  the  oil  reaches  the  sea.  On  Monday 
the  wind  was  not  so  strong  as  to  make  the  experiment  so 
complete  as  could  have  been  wished;  still,  there  was  a  heavy 
swell.  Early  in  the  forenoon  the  pumps  were  put  in  mo- 
tion and  the  leakage  space  in  the  pipe  filled;  but  unfortu- 
nately it  was  found,  soon  after  the  oil  began  to  rise  to  the 
surface  of  the  bay,  that  the  supply  in  the  cask  had  become 
exhausted,  and  those  who  were  conducting  the  experiment 
did  not  consider  themselves  at  liberty  to  order  a  fresh  cask 
of  oil  without  Mr.  Shield's  sanction.  But  while  the  ex- 
periment was  only  partial  it  was  highly  satisfactory.  At 
the  same  time,  the  film  did  not  extend  sufficiently  far  to 
prevent  the  waves  forming  and  curving  to  broken  water. 
As  soon,  however,  as  they  reached  the  oil-covered  neck  the 
observers  from  Ihe  pier-head  could  easily  discern  the  influ- 
ence at  work.  Waves  which  came  in  crested  gradually  as- 
sumed the  shape  of  undulating  bodies  of  water,  and,  once 
formed,  they  rolled  unbroken  towards  the  breakwater. 
On,  Wednesday  morning  there  was  a  heavy  sea  at  the  north 


290  SGIENCK  AY  SHORT  CHAPTERS. 

breakwater.  The  oil  valves  were  opened,  and  immediately 
the  effect  was  manifest.  The  waves,  which  had  before 
'dashed  with  fury  against  the  breakwater,  assumed  a  rolling 
motion  and  were  quite  crestless.  Indeed,  it  was  admitted 
that  the  oil  had  rendered  the  entrance  comparatively  safe, 
but  the  effect  was  not  so  abiding  as  could  have  been  wished." 

As  regards  the  want  of  duration  there  noted,  I  venture 
to  make  a  suggestion. 

Oils  vary  so  greatly  in  their  rate  of  outspreading  over 
water  and  the  character  of  the  film  they  form,  that  some 
years  ago  Mr.  Moffatt,  of  Glasgow,  proposed  to  use  these 
differences  as  a  test  for  the  adulterations  of  one  kind  of  oil 
with  other  and  cheaper  kinds. 

I  made  a  number  of  experiments  verifying  some  of  his 
results. 

From  these  it  is  evident  that  the  duration  of  the  becalm- 
ing effect  will  vary  with  different  oils,  and  therefore  further 
experiments  upon  these  difference  should  be  made,  in  order 
to  select  that  kind  which  is  the  most  effective,  with  due  re- 
gard, of  course,  to  cost. 

The  oil  indicated  by  my  experiments  as  combining  per- 
manency and  cheapness,  and  altogether  the  most  suitable 
and  attainable  is  the  "  dead  oil "  refuse  of  the  gas-works. 
This  may  be  used  in  its  crude  and  cheapest  condition. 


ON  THE   SO-CALLED    "CRATER    NECKS"   AND 
"VOLCANIC   BOMBS"  OF  IRELAND. 

A  PAPEK  READ  AT  THE  GEOLOGISTS'  ASSOCIATION, 
DECEMBER  6,  1878. 

MR.  HULL,  "  Physical  Geography  and  Geology  of  Ire- 
land," p.  68,  under  the  head  of  "Volcanic  Necks  and 
Basaltic  Dykes,"  says  that  "  although  the  actual  craters 
and  cones  of  eruption  have  been  swept  from  the  surface 
of  the  country  by  the  ruthless  hand  of  time,  yet  the  old 
' '  necks"  by  which  the  volcanic  mouths  were  connected 


"CRATER  XECK8"  AND   "VOLCANIC  BOMBS."  291 

with  the  sources  of  eruption  can  occasionally  be  recog- 
nized; they  sometimes  appear  as  masses  of  hard  trap,  col- 
umnar or  otherwise,  projecting  in  knolls  or  hills  above  the 
upper  surface  of  the  sheets  through  which  they  pierce." 

In  other  cases,  the  "  neck  "  consists  of  a  great  pipe  choked 
up  by  bombs  aud  blocks  of  trap,  more  or  less  consolidated, 
bombs  which  have  been  shot  into  the  air  and  have  fallen 
back  again.  He  then  refers  to  one  of  these  near  Portrush, 
and  proceeds  to  state  that  the  rock  on  which  stands  the 
ruined  Castle  of  Dun  luce,  "is  formed  of  bombs  of  all  sizes 
up  to  six  feet  in  diameter,  of  various  kinds  of  basalt,  dole- 
rite,  and  amygdaloid  firmly  cemented,  and  presenting  a 
precipitous  face  to  the  sea." 

In  a  note  dated  September,  1877,  Mr.  Hull  states  that 
subsequent  examination,  since  the  above  was  written,  of 
the  rock  of  Dunluce  Castle  and  the  cliffs  adjoining,  has  led 
him  "  to  suspect  that  we  have  here,  instead  of  old  volcanic 
necks,  simply  pipes,  formed  by  the  filtration  out  of  the 
chalk  into  which  the  basaltic  masses  have  fallen  and  slipped 
down,  thus  giving  rise  to  their  fragmental  appearance." 

Further  on  (page  14G)  he  describes  without  any  sceptical 
comment,  "the  remarkable  mass  of  agglomerate  made  up 
(as  on  the  southern  flanks  of  Slieve  Gullion)  of  bombs  of 
granite,  which  have  been  torn  up  from  the  granite  mass  of 
the  hills  below,  and  blown  through  the  throat  of  an  old 
crater."  Other  geologists  still  adhere  firmly  to  the  bomb 
theory,  some  ascribing  the  bombs  to  subaqueous  rather  than 
subaerial  ejection. 

Immediately  under  Dunluce  Castle  is  a  sea-worn  cavern 
or  tunnel,  which  is  about  40  or  50  feet  high  at  its  mouth, 
affording  a  fine  section  of  this  curious  conglomerate.  The 
floor  of  the  cavern  which  slopes  upwards  from  the  sea  is 
strewn  with  a  beach  of  boulders.  The  resemblance  of  this 
beach  to  those  I  had  recently  examined  at  the  foot  of  the 
boulder-clay  cliffs  of  Galway  Bay  (and  described  in  a  paper 
read  to  the  British  Association),  suggested  the  explanation 
of  the  origin  of  the  rock  I  am  about  to  offer. 

In  shape  and  size  they  are  exactly  like  the  Galway  shore 
boulders,  those  nearest  the  sea  being  the  most  rounded ; 
higher  up  the  slope,  where  less  exposed  to  wave  action,  they 


292  SCIENCE  IN  SHORT  CHAPTERS. 

are  subangular.  They  differ  from  the  Gal  way  boulders  in 
being  chiefly  basaltic  instead  of  being  mainly  composed  of 
carboniferous  limestone.  Some  of  these  at  Dunluce  are 
granitic,  and  a  few,  if  I  am  not  greatly  mistaken,  are  of 
carboniferous  limestone.  I  had  not  at  hand  the  means  of 
positively  deciding  this. 

Neither  could  I  find  any  unquestionable  examples  of 
glacial  striation  among  them,  though  at  the  upper  part  I 
saw  some  lines  on  boulders  that  were  very  suggestive  of 
partially  obliterated  scratches. 

On  looking  at  the  cavern  walls  surrounding  me  the 
theory  so  obviously  suggested  by  the  boulders  on  the  floor 
was  strikingly  confirmed  by  their  structure  and  general 
appearance.  The  imbedded  "bombs"  are  subangular,  and  of 
irregular  shape  and  varying  composition,  and  the  matrix 
of  the  rock  is  a  brick-like  material  just  such  as  would  be 
formed  by  the  baking  of  boulder  clay ;  the  inference  that 
I  was  looking  upon  a  bank  or  deposit  of  glacier  drift  that 
had  been  baked  by  volcanic  agency  was  irresistible. 

I  was  unable  to  see  on  any  part  of  the  extensive  section, 
or  among  the  fragments  below,  a  single  specimen  of  an  un- 
equivocal volcanic  bomb;  no  approach  to  anything  like 
those  described  by  Sir  Samuel  Baker  in  his  '"'Nile  Tribu- 
taries of  Abyssinia,"  the  miniature  representatives  of  which, 
ejected  from  the  Bessemer  converter,  I  have  figured  and 
described  in  Nature,  vol.  3,  pp.  389  and  410,  where  Sir 
Samuel  Baker's  description  is  quoted. 

I  have  witnessed  the  fall  of  masses  of  lava  during  a  minor 
eruption  of  an  inner  crater  of  Mount  Vesuvius.  These  as 
they  fell  upon  the  ground  around  me  were  flattened  out 
into  thin  cakes.  There  was  no  approach  to  the  formation 
of  subangular  masses,  like  those  displayed  upon  the  Dun- 
luce  cavern  walls. 

Some  years  ago  a  project  for  melting  the  basaltic  rock 
known  as  "  Rowley  Rag,"  and  casting  it  into  moulds  for 
architectural  purposes  was  carried  out  near  Oldbury,  and  I 
had  an  opportunity  of  watching  the  experiment,  which  was 
conducted  on  a  large  scale  at  great  expense  by  Messrs. 
Chance. 

It  was  found  that  if  the  basalt  cooled  rapidly  it  became 


"  CRATER  NECKS"  AND  "VOLCANIC  BOMBS."  293 

a  black  obsidian,  and  to  prevent  the  formation  of  such 
brittle  material,  the  castings,  and  the  moulds,  which  en- 
closed them,  had  to  be  kept  at  a  red-heat  for  some  days, 
and  very  gradually  cooled.* 

It  is  physically  impossible  that  lava  ejected  under  water, 
in  lumps  no  larger  than  these  boulders,  could  have  the 
granular  structure  which  they  display. 

The  fundamental  idea  upon  which  this  bomb  theory  is 
based  will  not  bear  examination.  Such  bombs  could  not 
have  been  shot  into  either  air  or  water  and  have  fallen  back 
again  into  the  volcanic  neck  at  any  other  time  than  during 
an  actual  eruption;  and  at  such  time  they  could  not  have 
remained  where  they  fell,  and  have  become  embedded  in 
any  such  matrix  as  now  contains  them.  True  volcanic 
bombs  and  ordinary  spattering  lumps  of  lava,  are,  as  AVC 
know,  flung  obliquely  out  of  active  craters,  and  distributed 
around,  while  those  which  are  ejected  perpendicularly  into 
the  air  and  return  are  re-ejected,  and  finally  pulverized  into 
volcanic  dust  if  this  perpendicular  ejection  and  return  are 
continued  long  enough. 

In  the  course  of  a  rapid  drive  round  the  Antrim  coast  I 
observed  other  examples  of  this  peculiar  conglomerate,  and 
have  reason  to  believe  that  it  is  far  more  common  than  is 
generally  supposed.  I  found  it  remarkably  well  displayed 
at  a  place  almost  as  largely  visited  as  the  Giant's  Causeway, 
and  where  it  nevertheless  appears  to  have  been  hitherto 
unnoticed,  viz.,  Carrick-a-Rede,'  where  the  public  car  stops 
to  afford  visitors  an  opportunity  of  examining  or  crossing 
the  rope  bridge,  etc. 

Here  the  whole  formation  is  displayed  in  a  manner  that 
strikingly  illustrates  my  theory. 

There  is  an  overlying  stream  of  basalt  forming  the  sur- 
face of  the  isolated  rock,  and  this  basalt  rests  directly  upon 
a  base  of  conglomerate,  having  exactly  the  appearence  that 


*  Geologists  who  maybe  interested  in  seeing  the  results  of  this 
experiment,  will  fiud  on  the  Edgbaston  Vestry  Hall,  inEnville  Road, 
near  the  Five  Ways,  Birmingham,  some  columns,  massive  window 
pieces,  doorways,  and  ornamental  steps  cast  from  the  fused  Rowley 
Rag  and  slowly  cooled. 


294  SCIENCE  IN  SHORT  CHAPTERS. 

would  result  from  the  slow  baking  of  a  mass  of  boulder 
clay. 

The  sea  gully  that  separates  the  insular  rock  from  the 
mainland  displays  a  fine  section  above  eighty  feet  in  thick- 
ness, and  has  the  advantage  of  full  daylight  as  compared 
with  Dunluce  Cave.  That  this  is  no  mere  neck  or  pipe  is 
evident  from  its  extent.  Its  position  below  the  basalt  cap 
refutes  the  above  quoted  subsequent  explanation,  which 
Mr.  Hull  and  others  have  recently  adopted. 

The  heterogeneous  bomb-like  character  of  the  boulders 
is  not  so  strongly  marked  as  in  the  Dunluce  rock,  and  this 
may  arise  from  the  closer  proximity  of  the  basalt,  which, 
coming  here  in  direct  contact,  would  be  likely  to  heat  the 
clay  matrix  (itself  formed  mainly  of  ice-ground  basalt)  to 
incipient  fusion,  and  thereby  render  it  more  like  the  basalt 
boulders  it  contains  than  the  other  clay  that  had  been  less 
intensely  heated  on  account  of  greater  distance  from  the 
lava-flow. 

The  path  leading  to  the  ladder  by  which  the  bridge  is 
approached  passes  over  such  conglomerate,  and  further 
extensions  are  seen  in  sections  around.  I  saw  sufficient  in 
the  course  of  my  hurried  visit  to  indicate  the  existence  of 
a  large  area  of  this  particular  formation. 

At  a  short  distance  from  Carrick-a-Rede,  on  the  way  to 
Ballycastle,  the  car  passes  in  sight  of  considerable  deposits 
of  ordinary  boulder  clay  uncovered  and  unaltered. 

The  blocks  of  basalt,  etc.,  embedded  in  this  correspond 
in  general  size  and  shape  with  the  "  bombs,"  excepting 
that  some  of  the  latter  have  a  laminated,  orshaly,  character 
near  their  surfaces. 

I  regret  my  inability  to  do  justice  to  this  subject  in  con- 
sequence of  the  fact  that  the  above  explanation  of  the  origin 
of  this  curious  formation  only  suggested  itself  when  hurry- 
ing homeward  after  a  somewhat  protracted  visit  to  Ireland. 
As  I  may  not  have  an  opportunity  of  further  investigation 
for  some  time  to  come,  I  offer  the  hypothesis  in  this  crude 
form  in  order  that  it  may  be  discussed,  and  either  con- 
firmed or  refuted  by  the  geologists  of  the  Ordnance  Survey, 
or  others  who  have  better  opportunities  of  observation  than 
I  can  possibly  command. 


"CRATER  NECKS"  AND  "VOLCANIC  BOMBS."  295 

Should  this  conglomerate  prove  to  be,  as  I  suppose,  a 
drift  deposit  altered  by  a  subsequent  flow  of  lava,  it  will 
supply  exceedingly  interesting  data  for  the  determination 
of  the  chronological  relations  of  the  glacial  epoch  to  that 
period  of  volcanic  activity  to  which  the  lavas  of  the  N.E. 
of  Ireland  are  due.  Though  it  will  nowise  disturb  the 
general  conclusion  that  the  great  eruptions  that  overspread 
the  cretaceous  rocks  of  this  region,  and  supplied  the 
boulders  of  my  supposed  metamorphosed  drift,  occurred 
during  the  Miocene  period,  it  will  show  that  this  volcanic 
epoch  was  of  vastly  greater  duration  than  is  usually  sup- 
posed; or  that  there  must  have  been  two  or  more  volcanic 
epochs — pre-glacial,  as  usually  understood,  and  post-glacial, 
in  order  to  supply  the  lava  overflowing  the  drift. 

This  post-glacial  extension  of  the  volcanic  period  has  an 
especial  interest  in  Ireland,  as  the  "  Annals  of  the  Four 
Masters,"  and  other  records  of  ancient  Irish  history  and 
tradition,  abound  in  accounts  of  physical  changes,  many  of 
which  correspond  remarkably  with  those  of  recent  occur- 
rence in  the  neighborhood  of  active  and  extinct  volcanoes. 

In  a  paper  read  before  the  Royal  Irish  Academy,  June 
23,  1873,  and  published  in  its  "Proceedings,"  Dr.  Sigerson 
has  collected  some  of  the  best  authenticated  of  these  ac- 
'counts,  and  compares  them  with  similar  phenomena  recent- 
ly observed  in  Naples,  Sicily,  South  America,  Siberia,  etc. 
.etc.  -The  "great  sobriety  of  diction,  and  circumstantial 
precision  of  statement,"  of  names,  dates,  etc.,  which  charac- 
terize, these  accounts  render  them  well  worthy  of  the  sort 
of  comparison  with  strictly  scientific  data  which  Dr.  Siger- 
son has  made. . 

As  we  now  know  that  man  existed  in  Britain  during  the 
inter-glacial,  if  not  the  pre-glacial  period,  and  as  so  violent 
a  volcanic  disturbance  as  that  which  poured  out  the  lavas 
of  Antrim  and  the  Mourne  district  could  scarcely  have 
subsided  suddenly,  but  was  probably  followed  by  ages  of 
declining  activity,  it  is  not  at  all  surprising  that  this  period 
of  minor  activity  should  have  extended  into  that  of  tradi- 
tion and  the  earliest  of  historical  records. 


296  SCIENCE  IN  SHORT  CHAPTERS. 


TRAVERTINE. 

THE  old  exclamation  about  Augustus  finding  Rome  of 
brick  and  leaving  it  of  marble,  deceives  many.  Ancienc 
Rome  was  by  no  means  a  marble  city,  although  the  quarries 
of  Massa  and  Carrara  are  not  far  distant.  The  staple- 
building  materials  of  the  Imperial  City,  even  in  its  palmi- 
est days,  were  brick  and  travertine.  The  brick,  however, 
was  very  different  from  the  porous  cakes  of  crudely  burnt 
clay  of  which  the  modern  metropolis  of  the  world  is  built. 
I  have  examined  on  the  spot  a  great  many  specimens,  and 
found  them  all  to  be  of  remarkably  compact  structure, 
somewhere  between  the  material  of  modern  terra-cotta  and 
that  of  common  flower-pots,  and  similarly  intermediate  in 
color.  The  Roman  builders  appear  to  have  had  no  standard 
size;  the  bricks  vary  even  in  the  same  building — the  Coli- 
seum for  example;  all  that  I  have  seen  are  much  thinner 
than  our  bricks — we  should  call  them  tiles. 

But  the  most  characteristic  material  is  the  travertine. 
The  walls  of  the  Coliseum  are  made  up  of  a  mixture  of 
this  and  the  tiles  above-mentioned.  The  same  is  the  case 
with  most  of  the  other  very  massive  ruins,  as  the  baths,  etc, 
Many  of  the  temples  with  columns  and  facing  of  marble 
have  inner  walls  built  of  this  mixture,  while  others  are 
entirely  of  travertine. 

I  was  greatly  surprised  at  the  wondrous  imperishability 
of  this  remarkable  material.  In  buildings  of  whioh  the 
smooth  crystalline  marble  had  lost  all  its  sharpness  and 
original' surface,  this  dirty,  yellow,  spongy-looking  lime- 
stone remained  without  the  slightest  indication  of  weather- 
ing. A  most  remarkable  instance  of  this  is  afforded  by  the 
temple  of  Neptune  at  Paestum,  in  Calabria.  This  is  the 
most  perfect  ruin  of  a  pure  classic  temple  that  now  remains 
in  existence,  and  in  my  opinion  is  the  finest.  I  prefer  it 
even  to  the  Parthenon. 

We  have  a  little  sample  of  it  in  London.  The  Doric 
columns  at  the  entrance  of  the  Euston  station  are  copies  of 
those  of  its  peristyle.  The  originals  are  of  travertine,  the 
blocks  forming  them  are  laid  upon  each  other  without 


TEA  VERTINE.  297 

mortar  or  cement,  and  BO  truly  flattened  that  in  walking 
round  the  building  and  carefully  prying,  I  could  find  no 
crevice  into  which  a  slip  of  ordinary  writing  paper,  or  the 
blade  of  a  pen-knife  could  be  inserted.  Yet  this  temple 
was  an  antiquarian  monument  in  the  days  of  the  Roman 
emperors. 

The  rough  natural  surface  of  the  stone  is  exposed,  and 
at  first  sight  appears  as  though  weathered,  but  this  appear- 
ance is  simply  due  to  its  natural  sponge-like  structure.  It 
appears  to  have  been  coated  with  some  sort  of  stucco  or 
smoothing  film,  which,  either  by  forming  a  thin  layer,  or 
possibly  by  only  filling  up  the  pores  of  the  travertine, 
gave  a  smooth  surface  upon  which  the  coloring  was  ap- 
plied. This  is  now  only  indistinctly  visible  here  and 
there,  and  if  I  remember  rightly,  some  have  disputed  its 
existence. 

But  this  travertine,  though  so  familiar  to  the  Italian,  is 
such  a  rarity  here  that  some  further  description  of  its 
structure  and  composition  may  be  demanded.  It  is  a  lime- 
stone formed  by  chemical  precipitation.  Most  limestones 
are  more  or  less  of  organic  origin,  are  agglomerations  of 
shells,  corals,  etc.,  but  this  is  formed  by  the  same  kind  of 
.action  as  that  which  produces  the  stalactites  in  limestone 
caverns.  It  has  some  resemblance  to  the  incrustation 
formed  on  boilers  by  calcareous  water.  Although  the  ma- 
terial of  so  many  ancient  edifices,  it  is,  geologically  speak- 
ing, the  youngest  of  all  the  hard  rocks.  Its  formation  is 
now  in  progress  at  some  of  the  very  quarries  that  supplied 
Imperial  Eome. 

On  the  Campagna,  between  Rome  and  Tivoli,  is  a  small 
circular  lake,  from  which  a  stream  of  tepid  water,  that 
wells  up  from  below,  is  continually  flowing.  Its  local  name 
is  the  "The  Lake  of  Tartarus. "  The  water,  like  that  of 
Zoedone,  or  soda-water  or  champagne,  is  supersaturated 
with  carbonic  acid  that  was  forced  into  it  while  under  pres- 
sure down  below.  This  carbonic  acid  has  dissolved  some 
of,  the  limestones  through  which  the  subterranean  water 
passes,  and  when  it  comes  to  the  surface,  the  carbonic  acid 
flies  away  like  that  which  escapes  when  we  uncork  a  bottle 
of  soda-water,  though  less  suddenly,  and  the  lime  losing  its 


298  SCIENCE  IN  SHORT  CHAPTERS. 

solvent  is  precipitated,  and  forms  a  crust  on  whatever  is 
covered  by  the  water. 

When  I  visited  this  lake  in  the  month  of  February  it  was 
surrounded  by  a  chevaux  defrise  of  an  extraordinary  char- 
acter; thousands  of  tribes  of  about  half  an  inch  to  one  inch 
in  diameter  outside,  with  calcareous  walls  about  one  eighth 
of  an  inch  in  thickness.  These  were  standing  up  from  two 
to  three  feet  high,  and  so  close  together  that  we  had  to 
break  our  way  through  the  dense  palisade  they  formed  in 
order  to  reach  the  margin  of  the  lake.  After  some  consider- 
ation and  inquiry,  their  origin  was  discovered.  They  are 
the  encrusted  remains  of  bullrusb.es  that  had  flourished  in 
the  summer  and  died  down  since.  During  the  time  of  their 
growth  the  water  had  risen,  and  thus  they  became  coated 
Avith  a  crust  of  compact  travertine.  This  deposition  takes 
place  so  rapidly  that  a  piece  of  lace  left  in  the  lake  for  a  few 
hours  comes  out  quite  stiff,  every  thread  being  coated  with 
limestone.  Such  specimens,  and  twigs  similarly  covered, 
are  sold  to  tourists  or  prepared  by  them  if  they  have  time 
to  stop.  Sir  Humphry  Davy  drove  a  stick  into  the  bottom 
of  the  lake  and  left  it  standing  upright  in  the  water  from 
May  to  the  following  April,  and  then  had  some  difficulty 
in  breaking  with  a  sharp  pointed  hammer  the  crust  formed 
round  the  stick.  This  crust  was  several  inches  in  thickness. 
That  which  I  saw  round  the  ex-bullrushes  may  have  all  been 
formed  in  a  few  days  or  weeks.  The  rivulet  that  flows  from 
the  lake  deposits  travertine  throughout  its  course,  and 
when  it  overflows  leaves  every  blade  of  grass  that  it  covers 
encrusted  with  this  limestone. 

Near  to  the  Lake  of  Tartarus  is  the  Solfatara  lake  which 
contains  similar  calcareous  water,  but  strongly  impregnated 
with  sulphureted  hydrogen;  it  consequently  deposits  a 
mixture  of  carbonate  and  sulphide  of  calcium,  a  sort  of 
porous  tufa,  some  of  it  so  porous  that  it  floats. like  a  stony 
scum,  forming  what  the  cicerone  call  "floating  islands." 
Lycll,  in  his  ''Principles  of  Geology,"  confounds  these 
lakes,  and  describes  Tartarus  under  the  name  of  Solfatara. 

The  travertine  used  as  a  building  stone  is  chiefly  derived 
from  the  quarries  of  Ponte  Lucano,  and  is  the  deposit  that 
was  formed  on  the  bed  of  a  lake  like  that  of  Tartarus.  The 


TEA  VERTINE.  299 

celebrated  cascade  of  the  Anio  at  Tivoli  forms  calcareous 
stalactites,  and  all  the  country  round  has  rivulets,  caverns, 
and  deposits,  where  this  formation  may  be  seen  in  progress 
or  completed. 

It  varies  considerably  in  structure,  some  specimens  are 
compact  and  smooth,  others  have  the  appearance  of  a  pet- 
rified moss,  and  great  varieties  may  be  found  among  the 
materials  of  a  single  building.  It  is,  however,  usually  rough 
and  more  or  less  spongy-looking,  as  above  stated,  but  this 
structure  does  not  seem  to  affect  its  stability,  at  least,  not 
in  the  climate  of  Italy.  Whether  it  would  stand  long  frosts 
is  an  open  question.  The  night  frosts  at  and  about  Home 
are  rather  severe,  but  usually  followed  by  a  warm  sunny 
day;  thus  there  is  no  great  penetration  of  ice. 

Every  specimen  I  have  examined  shows  a  remarkable 
compactness  of  molecular  structure  in  spite  of  visible  poro- 
sity. All  give  out  a  clear  metallic  ring  when  struck,  and 
the  intimate  surface,  if  I  may  so  describe  the  surface  of  the 
warm-like  structure  it  sometimes  displays,  is  always  clear 
and  smooth  as  though  varnished.  To  this  I  attribute  its 
durability.  Lest'the  above  description  should  appear  self- 
contradictory,  I  will  explain  a  little  further.  If  melted 
glass  were  run  into  threads,  and  those  threads  while  soft 
were  allowed  to  agglomerate  loosely  into  a  convoluted  mass, 
it  would,  as  regarded  in  mass,  have  a  porous  or  spongy- 
looking  structure,  but  nevertheless  its  molecular  structure 
would  be  compact  and  vitreous;  there  would  be  mechanical 
but  not  molecular,  porosity.  Travertine  is  similar. 

Have  we  any  travertine  in  England?  This  is  a  practical 
question  of  some  importance,  and  one  to  which  I  have  no 
hesitation  in  replying,  Yes.  There  is  plenty  formed  and 
forming  in  the  neighborhood  of  Matlock,  but  that  which  I 
have  seen  on  the  face  of  caverns,  etc.,  is  not  so  compact 
and  metal-like  as  the  Italian.  This,  however,  does  not 
prove  the  entire  absence  of  the  useful  travertine.  Not  hav- 
ing any  commercial  interest  in  the  search,  I  have  only 
looked 'at  what  has  come  in  my  way,  but  have  little  doubt 
that  there  are  other  kinds  besides  those  I  saw.  I  have  also 
seen  travertine  in  course  of  formation  in  Ireland,  where  I 
think  there  is  a  fine  field  for  exploration  in  the  mountain 


300  SCIENCE  IN  SHORT  CHAPTERS. 

limestone  regions,  which  have  been  disturbed  by  volcanic 
action  of  the  Miocene  period.  The  travertines  of  Italy  are 
found  in  the  neighborhood  of  extinct  volcanoes. 

The  classic  associations  of  this  material,  its  remarkable 
stability,  and  the  faculty  with  which  it  may  be  worked, 
render  it  worthy  of  more  attention  than  it  has  yet  received 
from  British  builders. 


THE  ACTION  OF  FROST  IN  WATER-PIPES  AND 
ON  BUILDING  MATERIALS. 

POPULAR  science  has  penetrated  too  deeply  now  to  render 
necessary  any  refutation  of  the  old  popular  fallacy  which 
attributed  the  bursting  of  water-pipes  to  the  thaw  follow- 
ing a  frost;  everybody  now  understands  that  the  thaw 
merely  renders  the  work  of  the  previous  freezing  so  disas- 
trously evident.  Nevertheless,  the  general  subject  of  the 
action  of  freezing  Avater  upon  our  dwellings  is  not  so  fully 
understood  by  all  concerned  as  it  should  be.  Builders  and 
house-owners  should  understand  it  thoroughly,  as  most  of 
the  domestic  miseries  resulting  from  severe  winters  may  be 
greatly  mitigated,  if  not  entirely  prevented,  by  scientific 
adaptation  in  the  course  of  building  construction.  Now- 
a-days  tenants  know  something  about  this  and  select  ac- 
cordingly. Thus  the  market  value  of  a  building  may  be 
increased  by  such  adaptation. 

Solids,  liquids,  and  gases  expand  as  they  are  heated. 
This  great  general  law  is,  however,  subject  to  a  few  excep- 
tions, the  most  remarkable  of  which  is  that  presented  by 
water.  Let  us  suppose  a  simple  experiment.  Imagine  a 
thermometer  tube  with  its  bulb  and  stem  so  filled  with 
water  that  when  the  water  is  heated  nearly  to  its  boiling 
point  it  will  rise  to  nearly  the  top  of  the  long  stein.  Now 
let  us  cool  it.  As  the  cooling  proceeds  the  water  will  de- 
scend, and  this  descending  will  continue  until  it  attains 
the  temperature  marked  on  our  ordinary  thermometer  as 
39°,  or  more  strictly  39^;  then  a  strange  inversion  occurs. 


THE  ACTION  OF  FROST  IX    WATER-PIPES.      301 

As  the  temperature  falls  below  this,  the  water  rises  gradu- 
Ually  in  the  stem  until  the  freezing  point  is  reached. 

This  expansion  amounts  to  ygV?  part  of  the  whole  bulk 
of  the  water,  or  100,000  parts  become  100,013.  So  far  the 
amount  of  expansion  is  very  small,  but  this  is  only  a  fore- 
taste of  what  is  coming.  Lower  the  temperature  still 
further,  the  water  begins  to  freeze,  and  at  the  moment  of 
freezing  it  expands  suddenly  to  an  extent  equalling  ^  of 
its  bulk,  i.e.,  of  the  bulk  of  so  much  water  as  becomes 
solidified.  The  temperature  remains  at  32°  until  the 
whole  of  the  water  is  frozen. 

Fortunately  for  us,  the  freezing  of  water  is  always  a  slow 
process,  for  if  this  conversion  of  every  15  gallons  into  16 
took  place  suddenly,  all  our  pipes  would  rip  open  with 
something  like  explosive  violence.  But  such  sudden  freez- 
ing of  any  considerable  quantity  of  water  is  practically  im- 
possible, on  account  of  the  "  latent  heat"  of  liquid  water, 
which  amounts  to  142£°.  All  this  is  given  out  in  the  act  of 
freezing.  It  is  this  giving  out  of  so  much  heat  that  keeps 
the  temperature-  of  freezing  water  always  at  32°,  even 
though  the  air  around  may  be  much  colder.  No  part  of 
the  water  can  fall  below  32°  without  becoming  solid,  and 
that  portion  which  solidifies  gives  out  enough  heat  to  raise 
142|  times  its  own  quantity  from  31°  to  32°. 

The  slowness  of  thawing  is  due  to  the  same  general  fact. 
An  instructive  experiment  may  be  made  by  simply  filling  a 
saucepan  with  snow  or  broken  ice,  and  placing  it  over  a 
common  fire.  The  slowness  of  the  thawing  will  surprise 
most  people  who  have  not  previously  tried  the  experiment. 
It  takes  about  as  long  to  melt  this  snow  as  it  would  to 
raise  an  equal  weight  of  water  from  32°  to  174°.  Or,  if  a 
pound  of  water  at  174°  be  mixed  with  a  pound  of  snow  at 
32°,  the  result  will  be  two  pounds  of  water  at  32°;  142° 
will  have  disappeared  without  making  the  snow  any 
warmer,  it  will  all  have  been  used  up  in  doing  the  work  of 
melting. 

The  force  with  which  the  great  expansion  due  to  freez- 
ing takes  place  is  practically  irresistible.  Strong  pieces  of 
ordnance  have  been  filled  with  water,  and  plugged  at  muz- 
zle and  touch-hole.  They  have  burst  in  spite  of  their  great 


302  SCIENCE  IN  SHORT  CHAPTERS. 

thickness  and  tenacity.  Such  being  the  case,  it  is  at  first 
sight  a  matter  of  surprise  that  frozen  water-pipes,  whether 
of  lead  or  iron,  ever  stand  at  all.  They  would  not  stand 
but  for  another  property  of  ice,  which  is  but  very  little  un- 
derstood, viz.,  its  viscosity. 

This  requires  some  explanation.  Though  ice  is  what  we 
call  a  solid,  it  is  not  truly  solid.  Like  other  apparent  sol- 
ids it  is  not  perfect  rigid,  but  still  retains  some  degree  of 
the  possibility  of  flowing  which  is  the  characteristic  of 
liquids.  This  has  been  shown  by  filling  a  bombshell  with 
water,  leaving  the  fuse-hole  open  and  freezing  it.  A  shell 
of  ice  is  first  formed  on  the  outside,  which  of  course  plugs 
up  the  fuse-hole.  Then  the  interior  gradually  freezes,  but 
the  expansion  due  to  this  forces  the  ice  out  of  the  fuse-hole 
as  a  cylindrical  stick,  just  as  putty  might  be  squeezed  out, 
only  that  the  force  required  to  mould  and  eject  the  ice  is 
much  greater. 

I  have  constructed  an  apparatus  which  illustrates  this 
very  strikingly.  It  is  an  iron  syringe  with  cylindrical  in- 
torior  of  about  half  an  inch  in  diameter,  and  a  terminal 
orifice  of  less  than  fa  of  an  inch  in  diameter.  Its  piston 
of  metal  is  driven  down  by  a  screw.  Into  this  syringe  I 
place  small  fragments  of  ice,  or  a  cylinder  of  ice  fitted  to 
the  syringe,  and  then  screw  down  the  piston.  Presently  a 
thin  wire  of  ice  is  squirted  forth  like  vermicelli  when  the 
dough  from  which  it  is  made  is  similarly  treated,  showing 
that  the  ice  is  plastic  like  the  dough,  provided  it  is  squeezed 
with  sufficient  force. 

This  viscosity  of  ice  is  displayed  on  a  grand  scale  in 
glaciers,  the  ice  of  which  actually  flows  like  a  river  down 
the  glacier  valley,  contracting  as  the  valley  narrows  and 
spreading  out  as  it  widens,  just  as  a  river  would;  but  moving 
only  a  few  inches  daily  according  to  the  steepness  of  the 
slope  and  the  season,  slower  in  winter  than  in  summer. 

Upon  this,  and  the  slowness  of  the  act  of  freezing,  de- 
pends the  possibility  of  water  in  freezing  in  iron  pipes  with- 
out bursting  them.  Even  iron  yields  a  little  before  burst- 
ing, but  ordinary  qualities  not  sufficiently  to  bear  the  ex- 
pansion of  -jV  of  their  contents.  What  happens  then  ?  The 
cylinder  of  ice  contained  in  the  tube  elongates  as  it  freezes, 


THE  ACTION  OF  FROST  IN  WATER-PIPES.      303 

provided  always  the  pipe  is  open  at  one  or  both  ends.  But 
there  is  a  limit  to  this,  seeing  that  the  friction  of  such  a 
tight-fitting  core,  even  of  slippery  ice,  is  considerable,  and 
if  the  pipe  be  too  long,  the  resistance  of  this  friction  may 
exceed  the  resistance  of  tenacity  of  the  pipe.  I  am  unable 
to  give  any  figures  for  such  length;  the  subject  does  not 
appear  to  have  been  investigated  as  it  should  be,  and  as 
it  might  well  be  by  our  wealthy  water  companies. 

We  all  know  that  lead  pipes  frequently  succumb,  but  a 
little  observation  shows  that  they  do  so  only  after  a  struggle. 
The  tenacity  of  lead  is  much  less  than  that  of  iron  (about 
•fa  of  that  of  ordinary  wrought  iron),  but  it  yields  consider- 
ably before  breaking.  It  has,  in  fact,  the  property  of  vis- 
cosity similar  to  that  of  ice.  At  Woolwich  the  lead  used 
for  elongated  rifle  bullets  is  squirted  like  the  ice  in  my 
syringe  above  described,  powerful  hydraulic  pressure  being 
used. 

This  yielding  saves  many  pipes.  It  would  save  all  new 
pipes  if  the  lead  were  pure  and  uniform  ;  but  as  this  is  not 
the  case,  they  may  burst  at  a  weak  place,  the  yielding  being 
shown  by  the  bulge  that  commonly  appears  at  the  broken 
part. 

From  the  above  it  will  be  easily  understood  that  a  pipe 
which  is  perfectly  cylindrical — other  conditions  equal — will 
be  less  likely  to  burst  than  one  whidh  is  of  varying  diameter, 
as  the  sliding  from  a  larger  to  a  smaller  portion  of  the  pipe 
must  be  attended  with  great  resistance,  or  a  certain  degree 
of  block,  beyond  what  would  be  due  to  the  mere  friction 
along  a  pipe  of  uniform  diameter. 

Let  us  now  consider  the  relative  merits  of  lead  and  iron 
as  material  for  Avater-pipes  in  places  where  exposure  to  frost 
is  inevitable.  Lead  yields  more  than  iron,  and  so  far  has 
an  advantage;  this,  however  is  but  limited.  As  lead  is 
practically  inelastic,  every  stretch  remains,  and  every  stretch 
diminishes  the  capacity  for  further  stretching;  the  lead  thus 
stretched  at  one  frost  is  less  able  to  stretch  again,  and  has 
lost  some  of  its  original  tenacity.  Hence  the  superiority  of 
new  leaden  pipes.  Iron  is  elastic  within  certain  limits,  and 
thus  the  iron  pipe  may  yield  a  little  without  permanent 
strain  or  "distress,"  and  if  its  power  of  elastic  resistance 


304  SCIENCE  IN  SHORT  CHAPTERS. 

is  not  exceeded,  it  regains  its  original  size  without  becoming 
sensibly  weaker.  Add  to  this  its  great  tenacity,  its  non- 
liability to  be  indented,  or  otherwise  to  vary  in  diameter, 
and  we  have  a  far  superior  material. 

But  this  conclusion  demands  some  qualification.  There 
is  iron  and  iron,  cast-iron  and  wrought-iron,  and  very  vari- 
able qualities  of  each  of  these.  I  need  scarcely  add  that 
common  brittle  cast-iron  is  quite  out  of  the  question  for 
such  purposes,  though  there  is  a  new  kind  of  cast-iron  or 
semi-steel  coming  forward  that  may  possibly  supersede  all 
other  kinds;  but  this  opens  too  wide  a  subject  for  discus- 
sion in  the  present  paper,  the  main  object  of  which  has 
been  a  popular  exposition  of  the  general  physical  laws  which 
must  be  obeyed  by  the  builder,  or  engineer,  who  desires  to 
construct  domestic  or  other  buildings  that  will  satisfy  the 
wants  of  intelligent  people. 

The  mischievous  action  of  freezing  water  is  not  confined 
to  the  pipes  that  are  constructed  to  receive  or  convey  it. 
Wherever  water  may  be,  if  that  water  freezes,  it  must  ex- 
pand in  the  degree  and  with  the  force  already  described. 
If  it  penetrates  stone  or  brick,  or  mortar  or  stucco,  and 
freezes  therein,  one  of  two  things  must  occur — either  the 
superfluous  ice  must  exude  at  the  surface  or  to  neighbor- 
ing cavities,  or  the  saturated  material  must  give  way,  and 
split  or  crumble  according  to  the  manner  and  degree  of 
penetration.  To  understand  this,  the  reader  must  remem- 
ber what  I  stated  about  the  little-understood  viscosity  of 
ice,  as  well  as  its  expansion  at  the  moment  of  freezing. 

Bricks  are  punished,  but  not  so  severely  as  might  be 
anticipated,  seeing  how  porous  are  some  of  the  common 
qualities,  especially  those  used  in  London.  They  are  so 
amply  porous  that  the  water  not  only  finds  its  way  in  to 
them,  but  the  pores  are  big  enough  and  many  enough  for 
the  ice  to  demonstrate  its  viscosity  by  squeezing  out  and 
displaying  its  crystalline  structure  in  the  form  of  snow- 
like  efflorescence  on  the  surface.  This  may  have  been  ob- 
served by  some  of  my  readers  during  a  severe  frost.  It  is 
commonly  confounded  with  the  hoar-frost  tliat  whitens  the 
roofs  of  houses,  but  which  is  very  rarely  deposited  on  per- 
pendicular wall  faces. 


THE  ACTION  OF  FROST  IN  WATER-PIPES.      305 

The  mortar  most  liable  to  suffer  is  that  which  is  porous 
and  pulverulent  within,  but  has  been  cleverly  faced  or 
pointed  with  a  crust  of  more  compact  material.  This 
outer  film  prevents  the  exuding  of  the  expanding  ice  crys- 
tals, is  thrust  forth  bodily,  and  retained  by  ice-cement 
during  the  frost,  but  it  falls  in  scales  when  this  temporary 
binding  material  thaws.  Mortar  that  is  compact  through- 
out does  not  suffer  to  any  appreciable  extent.  This  is 
proved  by  the  condition  of  the  remains  of  Roman  brick- 
work that  still  exist  in  Britain  and  other  parts  of  Europe. 
Some  of  the  old  shingle  walls  at  Brighton  and  other  parts 
of  the  south  coast,  where  the  chalk  for  lime-burning  was 
at  the  builder's  feet,  and  where  his  mortar  is  so  thickly 
laid  between  the  irregular  masses  of  flint,  also  show  the 
possible  duration  of  good  mortar.  The  jerry  builder's 
mortar,  made  of  the  riddlings  of  burnt  clay  ballast  and 
dust-hole  refuse  just  flavored  with  lime,  crumbles  imme- 
diately, because  these  materials  do  not  combine  with  the 
lime  as  fine  siliceous  sand  gradually  does,  to  form  an  im- 
permeable glassy  silicate. 

Stucco  is  punished  by  two  distinct  modes  of  action. 
The  first  is  where  the  surface  is  porous,  and  the  water  per- 
meates accordingly  and  freezes.  This,  of  course,  produces 
superficial  crumbling,  which  should  not  occur  at  all  upon 
good  material  protected  by  suitable  paint.  The  other  case, 
very  deplorable  in  many  instances,  is  where  the  water  finds 
a  space  between  the  inner  surface  of  the  stucco  and  the 
outer  surface  of  the  material  upon  which  it  is  laid.  This 
water,  when  frozen,  of  course,  expands,  and  wedges  away 
the  stucco  bodily,  causing  it  to  come  down  in  masses  at  the 
thaw.  This,  however,  only  occurs  after  severe  frosts,  as 
the  ordinary  mild  frosts  of  our  favored  climate  seldom  en- 
dure long  enough  to  penetrate  to  any  notable  depth  of  so 
bad  a  conductor  as  stone  or  stucco.  It  is  worthy  of  note 
that  water  is  a  still  worse  conductor  than  stone. 

Building  stones  are  so  various  both  in  chemical  composi- 
tion and  mechanical  structure  that  the  action  of  freezing 
water  is  necessarily  as  varied  as  the  nature  of  the  material. 
The  highly  siliceous  granites  (or,  rather,  porphyries  that 
commonly  bear  the  name  of  granite)  are  practically  imper* 


306  SCIENCE  IN  SHORT  CHAPTERS. 

ineable  to  water  so  long  as  they  are  free  from  any  chemical 
decomposition  of  their"  feldspathic  constituents;  but  when 
we  come  to  sandstones  and  limestones,  or  intermediate  ma- 
terial,, very  wide  differences  prevail. 

The  possible  width  of  this  difference  is  shown  in  the 
behavior  of  the  unselected  material  in  its  natural  home. 
Certain  cliffs  and  mountains  have  stood  for  countless  ages 
almost  unchanged  by  the  action  of  frost;  others  are  break- 
ing up  with  attonishing  rapidity  in  spite  .of  apparent  solid- 
ity of  structure.  The  Matterhorn,  or  Mont  Cervin,  one  of 
the  most  gigantic  of  the  giant  Alps,  15,200  feet  high,  is 
rendered  especially  dangerous  to  ambitious  climbers  by  the 
continual  crashing  down  of  fragments  that  are  loosened 
when  the  summer  sun  melts  the  ice  that  first  separated  and 
then  for  awhile  held  them  in  their  original  places.  All  the 
glaciers  of  the  Alps  are  more  or  less  streaked  with 
•'moraines,"  which  are  fragments  of  the  mountains  that 
freezing  water  has  detached. 

Our  stone  buildings  would  suffer  proportionally  if  some 
selection  of  material  were  not  made.  Generally  speaking, 
this  selection  is  based  upon  the  experience  of  previous  prac- 
tical trials.  Certain  quarries  are  known  to  have  supplied 
good  material  of  a  certain  character,  and  this  quarry  has, 
therefore,  a  reputation  which  is  usually  of  no  small  value 
to  its  fortunate  owner.  Other  quarries  are  opened  in  the 
neighborhood  wherever  the  rock  resembles  that  of  the  tested 
quarry. 

Sometimes,  however,  materials  are  open  for  selection 
that  have  not  been  so  well  tested,  and  a  method  of  testing 
which  is  more  expeditious  and  less  expensive  than  con- 
structing a  building  and  watching  the  result,  is  very  de- 
sirable. The  subject  of  testing  building  materials  in  spe- 
cial reference  to  their  resistance  of  frost  was  brought  be- 
fore the  Academy  of  Science  of  Paris  by  M.  Brard  some 
years  since. 

In  his  preliminary  experiments  he  used  small  cubes  of 
the  stone  to  be  tested,  soaked  them  in  water,  and  then  ex- 
posed them  to  the  air  in  frosty  weather,  or  subjected  them 
to  the  action  of  freezing  mixtures.  Afterwards  he  found 
ihat  by  availing  himself  of  the  expansive  force  which  cer- 


THE  ACTION  OF  FROST  IN   WATER-PIPES.      307 

tain  saline  solutions  exert  at  the  moment  of  crystallization, 
he  could  conveniently  imitate  the  action  of  freezing  with- 
out the  aid  of  natural  or  artificial  frost.  Epsom  salts, 
nitre,  alum,  sulphate  of  iron,  Glauber's  salts,  etc.,  were 
tried.  The  last  named,  Glauber's  salt  (or  sulphate  of 
soda),  which  is  very  cheap,  was  found  to  be  the  best  for 
the  purpose. 

His  method  of  applying  the  test  is  as  follows:  Cut  the 
specimens  into  two-inch  cubes,  with  flat  sides  and  sharp 
edges  and  corners,  mark  each  specimen  with  a  number, 
either  by  ink  or  scratching,  and  enter  in  a  book  all  particu- 
lars concerning  it.  Make  a  saturated  solution  of  the  sul- 
phate of  soda  in  rain  or  distilled  water,  by  adding  the  salt 
until  no  more  will  dissolve;  perfect  saturation  being  shown 
by  finding,  after  repeated  stirring,  that  a  little  of  the  salt 
remains  at. the  bottom  an  hour  or  two  after  the  solution 
was  made.  Heat  this  solution  in  a  suitable  vessel,  and 
when  it  boils  put  in  the  marked  specimens  one  by  one,  and 
keep  them  immersed  in  the  boiling  solution  for  half  an 
hour.  Take  out  the  specimens  separately  and  suspend 
them  by  threads,  each  over  a  separate  vessel  containing 
some  of  the  liquid  in  which  they  were  boiled,  but  which 
has  been  carefully  strained  to  free  it  from  any  solid  parti- 
cles. In  the  course  of  a  day  or  two,  as  the  cubes  dry,  they 
will  become  covered  with  an  efflorescence  of  snow-like  crys- 
tals; wash  these  away  by  simply  plunging  the  specimen  into 
the  vessel  below,  and  repeat  this  two  or  three  times  daily 
for  four  or  five  days  or  longer.  The  most  suitable  vessel 
for  the  purpose  is  a  glass  "  beaker,"  sold  by  vendors  of 
chemical  apparatus. 

In  comparing  competing  samples,  be  careful  to  treat  all 
alike,  i.e.,  boil  them  together  in  the  same  solution,  and  dip 
them  an  equal  number  of  times  at  equal  intervals. 

Having  done  this,  the  result  is  now  to  be  examined.  If 
the  stone  is  completely  resistant  the  cube  will  remain 
smooth  on  its  surfaces  and  sharp  at  its  edges  and  corners, 
and  there  will  be  no  particles  at  the  bottom  of  the  vessel. 
Otherwise,  the  inability  of  the  stone  to  resist  the  test  will 
be  shown  by  the  disfigurement  of  the  cube  or  the  small 
particles  wedged  off  and  lying  at  the  bottom  of  the  liquid. 


308  SCIENCE  IN  SHORT  CHAPTERS. 

Cure  must  be  taken  not  to  confound  these  with  crystals  of 
the  salt  which  may  also  be  deposited.  These  crystals  are 
easily  removed  by  adding  a  little  more  water  or  warming 
the  solution. 

For  strict  comparison  the  fragments  thus  separated 
should  be  weighed  in  a  delicate  balance,  such  as  is  used  in 
chemical  analysis. 


THE  COKROSION  OF  BUILDING  STOKES. 

ABOUT  fifty  years  ago  two  eminent  French  chemists 
visited  London,  and  rather  "astonished  the  natives"  by  a 
curious  feature  of  their  dress.  They  wore  on  their  hats 
large  patches  of  colored  paper.  Coming,  as  they  did,  from 
Paris,  many  supposed  that  this  was  one  of  the  latest  Paris 
fashions,  and  the  dandies  of  the  period  narrowly  escaped 
the  compulsion  to  follow  it.  They  probably  would  have 
done  so  had  the  Frenchmen  shown  any  attempt  at  decora- 
tive shaping  of  the  paper.  They  neglected  this  because  it 
was  litmus  paper,  and  their  object  in  attaching  it  to  their 
hats  was  to  test  the  impurities  of  the  London  atmosphere. 

Blue  litmus  paper,  as  everybody  knows  now-a-days,  turns 
red  when  exposed  to  an  acid.  The  French  chemists  found 
that  their  hat-decorations  changed  color,  and  indicated  the 
presence  of  acid  in  the  air  of  London;  but  when  they  left 
the  metropolis  and  wandered  in  the  open  fields  their  blue 
litmus  paper  retained  its  original  color.  By  using  alkaline 
paper  they  contrived  to  collect  enough  of  the  acid  to  test 
its  composition.  They  found  it  to  be  the  acid  which  is 
formed  by  the  burning  of  sulphur,  and  attributed  its  exist- 
ence to  the  sulphur  of  our  coal.  At  this  time  the  domestic 
use  of  coal  was  scarcely  known  in  Paris. 

Subsequent  experiments  have  proved  that  they  were 
right;  that  the  air  of  London  contains  a  very  practical 
quantity  of  sulphurous  and  sulphuric  acids,  which  are  due 
to  the  combustion  of  that  yellow  shining  material  more  or 
less  visible  in  most  kinds  of  coal,  and  has  been  occasionally 
supposed  to  be  gold.  It  is  iron  pyrites,  a  compound  of  iron 


THE  CORROSION  OF  BUILDING  STONES.        309 

and  sulphur.  When  heated  the  sulphur  is  separated  and 
burns,  producing  sulphurous  acid,  which,  exposed  to  moist 
air,  gradually  takes  up  more  oxygen  and  becomes  sulphuric 
acid,  which  in  concentrated  solution  is  oil  of  vitriol.  In 
the  air  it  is  very  much  diluted  by  diffusion,  but  is  still 
strong  enough  to  do  mischief  to  some  kinds  of  building 
materials. 

In  manufacturing  towns,  such  as  Birmingham  and  Shef- 
field, the  quantity  of  this  acid  in  the  air  is  much  greater 
than  in  London,  and  there  its  mischief  is  consequently 
more  distinctly  visible.  The  church  of  St.  Philip,  which 
stands  nearly  in  the  middle  of  Birmingham,  and  is  sur- 
rounded by  an  old  churchyard,  was  so  corroded  by  this  acid 
that  the  stone  peeled  away  on  all  sides,  and  its  condition 
was  most  deplorable.  The  tombstones  were  similarly  dis- 
integrated 011  their  surfaces,  and  inscriptions  quite  obliter- 
ated. It  became  so  bad  that  a  few  years  ago  restoration 
was  necessary,  and  it  was  newly  faced  accordingly. 

Some  of  the  old  tombstones  that  are  preserved  may  still 
be  seen  against  the  church  wall,  and  their  peculiar  structure 
is  well  worthy  of  study.  They  display  a  lamination  or 
peeling  away  due  to  unequal  corrosion,  certain  layers  of  the 
material  of  the  stone  having  been  evidently  eaten  away 
more  rapidly  than  others.  Anybody  visiting  Birmingham 
may  easily  examine  these,  as  St.  Philip's  churchyard  is 
situated  between  the  two  railway  stations  of  New  Street 
and  Snow  Hill,  and  is  but  two  minutes'  walk  from 
either. 

Other  stone  buildings  in  the  town  have  suffered,  but  in 
very  different  degrees,  and  some  have  quite  escaped,  prov- 
ing the  necessity  of  careful  selection  of  material  wherever 
coal  fires  abound.  In  Birmingham  the  action  of  coal  fires 
is  assisted  by  other  sources  of  acid  vapor.  The  process  of 
"pickling"  brass  castings,  i.e.,  brightening  their  surface, 
by  dipping  first  in  common  nitric  acid  ("'pickle  acky") 
and  then  in  water,  is  attended  with  considerable  evolution 
of  acid  fumes.  Besides  this  very  widespread  use  of  acid, 
there  are  several  chemical  manufactories  that  throw  still 
more  acid  into  the  air  immediately  surrounding  them. 

As  an  example  of  the  action  of  the  atmospheric  acids  of 


310  SCIENCE  IN  SHORT  CHAPTERS. 

London  upon  building  stones,  I  have  but  to  name  the 
Houses  of  Parliament,  which  have  only  been  rescued  from 
superficial  ruin  by  the  patchwork  replacing  of  certain 
blocks  of  stone,  and  various  devices  of  siliceous  and  other 
washings  that  have  been  carried  out  at  great  cost  to  the 
nation.  That  such  an  unsuitable  material  should  have 
been  used  is  disgraceful  to  all  concerned.  The  ruin  com- 
menced before  the  building  was  finished.  At  the  time 
when  its  erection  commenced  there  were  abundant  evi- 
dences of  the  ruinous  action  of  London  atmosphere  on 
some  kinds  of  stone  and  the  capability  of  others  to  resist 
it,  for  while  many  modern  buildings  are  peeling  and  crum- 
bling, some  of  the  oldest  in  the  midst  of  the  city  show 
scarcely  any  signs  of  corrosion. 

The  Birmingham  and  Midland  Institute  was  established 
and  in  practical  operation  a  few  years  before  the  present 
noble  building  was  erected.  I  was  the  first  teacher  there 
and  conducted  the  Science  classes  in  the  temporary  premises 
in  Cannon  street.  Having  observed  with  some  interest 
the  disintegration  of  St.  Philip's  Church  and  other  build- 
ings, I  was  anxious  for  the  safety  of  the  new  Institute 
buildings,  and  accordingly  made  some  experiments  upon 
the  material  proposed  to  be  used  by  the  architect.  My 
method  of  testing  was  very  simple,  and  as  the  practical 
result  has  verified  my  anticipations  I  think  it  might  be 
adopted  by  others. 

First,  I  immersed  some  lumps  of  the  stone  in  moderately 
strong  solutions  of  sulphuric  and  hydrochloric  acids  suc- 
cessively, and  observed  whether  any  visible  action  occurred 
after  some  days.  There  was  none.  I  then  roughly  tested 
the  crushing  pressure  of  small  samples  in  their  natural 
state,  and  subjected  similar  sized  pieces  to  the  same  test 
after  they  had  been  immersed  in  the  acids.  I  found  thus 
that  there  were  no  evidences  of  internal  disintegration  even 
after  several  days'  immersion,  and  therefore  inferred  that 
the  stone  would  stand  the  acid  vapors  of  the  Birmingham 
atmosphere.  This  has  been  the  case  with  that  portion  of 
the  building  that  was  built  of  the  material  I  tested.  As  I 
know  nothing  of  the  stone  which  is  used  for  the  extension 
of  the  building  under  the  present  architect,  Mr.  Chamber- 


THE  CORROSION  OF  BUILDING  STORES.        311 

lain,  I  am  unable  to  make  any  forecast  of  its  probable  dura- 
bility. 

The  experiments  I  made  at  the  time  named  with  this 
and  other  building  materials  justified  the  conclusion  that 
the  worst  of  all  material  for  exposure  to  acid  atmospheres 
is  a  sandstone,  the  particles  of  which  are  held  together  by 
limestone,  or  are  otherwise  surrounded  by  or  intermingled 
with  limestone;  and  that  the  best  of  ordinary  material  is  a 
pure  sandstone  quite  free  from  lime.  I  do  not  here  con- 
sider such  luxurious  material  as  granite  or  porphyries. 

Compact  limestone,  such  as  good  homogeneous  marble, 
stands  fairly  well,  although  itis  slowly  corroded.  The  corro- 
sion, however,  in  this  case,  is  purely  superficial  and  tolerably 
uniform.  .It  is  a  very  slow  washing  away  of  the  surface, 
without  any  disintegration  such  as  occurs  where  a  small 
quantity  of  limestone  acts  as  binding  material  to  hold  to- 
gether a  large  quantity  of  siliceous  or  sandy  material,  and 
where  the  agglomeration  is  porous,  and  the  stone  is  so  laid 
that  a  downward  infiltration  of  water  can  take  place;  for  it 
must  be  remembered  that  although  the  acid  originally  ex- 
ists as  vapor  in  the  ah',  it  is  taken  up  by  the  falling  rain, 
and  the  mischief  is  directly  done  to  the  stone  by  the  acidi- 
fied water.  This,  of  course,  is  very  weak  acid  indeed. 
That  which  I  used  for  testing  the  stone  was  many  thousand 
times  stronger,  but  then  I  exposed  the  stone  for  only  a  few 
days  instead  of  many  thousand  days. 

As  above  stated,  my  experiments  were  but  rude,  but  I 
think  it  would  be  quite  worth  while  to  construct  crushing 
apparatus  capable  of  registering  accurately  the  pressure 
used,  and  to  operate  with  standard  solutions  of  acid  upon 
carefully  squared  blocks  of  standard  size,  and  thus  to  make 
comparative  tests  of  various  samples  of  stone  when  competi- 
tions for  building  materials  are  offered.  In  the  case  of  the 
Birmingham  and  Midland  Institute  building  there  was  no 
such  competition,  the  choice  was  left  entirely  to  the  archi- 
tect, and  my  examination  was  unofficially  conducted  upon 
the  material  already  chosen  with  the  .intent  of  protesting  if 
it  failed.  As  it  stood  the  test  I  merely  reported  the  results 
informally  to  the  architect,  the  late  Sir  Edward  Barry,  no 
further  action  being  demanded. 


312  SCIENCE  IN  SHORT  CHAPTERS. 


FIRE-CLAY  AND  ANTHRACITE. 

FOR  household  fire-places,  whether  open  or  closed,  these 
may  be  regarded  as  the  material  and  the  fuel  of  the  future, 
and  should  be  more  generally  and  better  understood  than 
they  are. 

The  merits  of  fire-clay  were  fully  appreciated  and  de- 
scribed nearly  a  hundred  years  ago  by  that  very  remarkable 
man,  Benjamin  Thompson,  Count  of  Rumford.  Any  sound 
scientific  exposition  of  the  relative  value  of  fire-clay  and 
iron  as  fire-place  materials  can  be  little  more  or  less  than  a 
repetition  of  what  he  struggled  to  teach  at  the  beginning 
of  the  present  century. 

It  is  impossible  to  fairly  understand  this  subject  unless 
we  start  with  a  firm  grasp  of  first  principles.  The  business 
before  us  is  to  get  as  much  heat  as  possible  from  fuel  burn- 
ing in  a  certain  fashion,  and  to  do  this  with  the  smallest 
possible  emission  of  smoke. 

Substances  that  are  hotter  than  their  surroundings  com- 
municate their  excess  of  temperature  in  three  different 
ways;  1st,  by  Conduction;  2d,  by  Convection;  3d,  by  Radia- 
tion. All  of  these  are  operating  in  every  form  of  fire-place, 
but  in  very  different  proportions  according  to  certain  vari- 
ations of  construction. 

To  demonstrate  the  conduction  of  heat,  hold  one  end  of 
a  pin  between  the  finger  and  thumb,  and  the  other  end  in 
the  flame  of  a  candle.  The  experiment  will  terminate 
very  speedily.  Then  take  a  piece  of  a  lucifer  match  of  the 
same  length  as  the  pin,  and  hold  that  in  the  candle.  This 
may  become  red-hot  and  flaming  without  burning  the 
fingers,  as  the  pin  did  at  a  much  lower  temperature.  It 
matters  not  whether  the  pin  be  held  upwards,  downwards, 
or  sideways,  the  heat  will  travel  throughout  its  substance, 
and  this  sort  of  traveling  is  called  "conduction,"  and  the 
pin  a  "  conductor"  of  heat.  The  conducting  power  of  dif- 
ferent substances  varies  greatly,  as  the  above  experiment 
shows.  Metals  generally  are  the  best  conductors,  but  they 
differ  among  themselves;  silver  is  the  best  of  all,  copper 


FIRE-CLAY  AND  ANTHRACITE.  313 

the  next.  Calling  (for  comparison  sake)  the  conductivity 
of  silver  1000,  that  of  copper  is  736,  gold  532,  brass  236, 
iron  119,  marble  and  other  building  stones  6  to  12,  porce- 
lain 5,  ordinary  brick  earth  only  4,  and  fire-brick  earth 
less  than  this.  Thus  we  may  at  once  start  upon  our  sub- 
ject, with  the  practical  fact  that  iron  conducts  heat  thirty 
times  more  readily  than  does  fire-brick. 

Convection  is  different  from  conduction,  inasmuch  as  it 
is  effected  by  the  movements  of  the  something  which  has 
been  heated  by  contact  with  something  else.  Water  is  a 
very  bad  conductor  of  heat,  much  worse  than  fire-brick, 
and  yet,  as  we  all  know,  heat  is  freely  transmitted  by  it,  as 
when  we  boil  water  in  a  kettle.  If,  however,  we  placed 
the  water  in  a  fire-clay  kettle,  and  applied  the  heat  at  the 
top  we  should  have  to  wait  for  our  tea  until  to-morrow  or 
the  next  day.  When  the  heat  is  applied  below,  the  hot 
metal  of  the  kettle  heats  the  bottom  film  of  water  by  direct 
contact ;  this  film  expands,  and  thus,  being  lighter,  rises 
through  the  rest  of  the  water,  heating  other  portions  by 
contact  as  it  meets  them,  and  so  on  throughout.  The  heat 
is  thus  conveyed,  and  the  term  "convection"  is  based  on 
the  view  that  each  particle  is  a  carrier  of  heat  as  it  proceeds. 
Air  conveys  heat  in  the  same  manner ;  so  may  all  gases  and 
liquids,  but  no  such  convection  is  possible  in  solids.  The 
common  notion  that  "  heat  ascends"  is  based  on  the  well- 
known  facts  of  convection.  It  is  the  heated  gas  or  liquid 
that  really  ascends.  No  such  preference  is  given  to  an 
upward  direction,  when  heat  is  conducted  or  radiated. 

Radiation  is  a  flinging  off  of  heat  in  all  directions  by  the 
heated  body.  Radiation  from  solids  is  mainly  superficial, 
and  it  depends  on  the  nature  of  the  heated  surface.  The 
rougher  and  the  more  porous  the  surface  of  a  given  sub- 
stance the  better  it  radiates.  Bright  metals  are  the  worst 
radiators ;  lampblack  the  best,  and  fire-brick  nearly  equal 
to.  it.  To  show  the  effect  of  surface,  take  three  tin  canisters 
of  equal  size,  one  bright  outside,  the  second  scratched  and 
roughened,  the  third  painted  over  with  a  thin  coat  of  lamp- 
black. Fill  each  with  hot  water  of  the  same  temperature, 
and  leave  them  equally  exposed.  Their  rates  of  radiation 
will  then  be  measurable  by  their  rates  of  cooling.  The 


314  SCIENCE  IN  SHORT  CHAPTERS. 

black  will  cool  the  most  rapidly,  the  rough  canister  next, 
and  the  bright  one  the  slowest* 

Radiant  heat  may  be  reflected  like  light  from  bright 
surfaces,  the  reflecting  substance  itself  becoming  heated  in 
a  proportion  which  diminishes  just  as  its  reflecting  powers 
increase.  Good  reflectors  are  bad  radiators  and  bad  ab- 
sorbers of  heat,  and  the  power  of  absorbing  heat,  or  becom- 
ing superficially  hot  when  exposed  to  radiant  heat,  is  exactly 
proportionate  to  radiating  efficiency. 

Fire-clay  is  a  good  absorber  of  radiant  heat,  i.e.,  it  becomes 
readily  heated  when  near  to  hot  coals  or  flames,  without 
requiring  actual  contact  with  them.  It  is  an  equally  good 
radiator. 

Let  us  now  apply  these  facts  to  fire-clay  in  fireplaces, 
beginning  with  ordinary  open  grates  used  for  the  warming 
of  apartments ;  first  supposing  that  we  have  an  ordinary 
old-fashioned  grate  all  made  of  iron — front,  sides,  and  back, 
as  well  as  bars,  and  next  that  we  have  another  of  similar 
form  and  position,  but  all  the  fire-box  and  the  back  and 
cheeks  of  the  grate  made  of  fire-clay. 

It  is  evident  that  the  fire-clay  not  in  actual  contact  with 
the  coals,  but  near  to  them,  will  absorb  more  heat  than  the 
iron,  and  thus  become  hotter.  Even  at  the  same  temperature 
it  will,  radiate  much  more  heat  than  iron,  but  being  so  much 
hotter  this  advantage  will  be  proportionately  increased.  An 
open  fireplace  lined  throughout  with  fire-clay  thus  throws 
into  the  room  a  considerable  amount  of  its  own  radiation 
in  addition  to  that  thrown  out  from  the  coal. 

But  what  becomes  of  this  portion  of  the  heat  When  the 
fireplace  is  all  of  metal?  It  is  carried  up  the  chimney  by 
convection,  for  the  metal,  while  it  parts  with  less  heat  by 
radiation,  gives  up  more  to  the  air  by  direct  contact.  There- 
fore, if  wo  must  burn  our  coals  inside  the  chimney,  we  lose 
less  by  burning  them  in  a  fire-clay  box  than  in  a  metal 
box. 

Count  Rumford  demonstrates  this,  and  described  the 
best  form  of  open  firegrate  that  can  be  placed  in  an  ordinary 
English  hole-in-the-wall  fireplace.  The  first  thing  to  be 
done,  according  to  his  instructions,  is  to  brick  up  your  large 
square  fireplace  recess,  so  that  the  back  of  it  shall  come 


FIRE-CLAY  AND  ANTHRACITE.  315 

forward  to  about  4  inches  from  the  front  inside  face  of  the 
chimney,  thus  contracting  the  throat  of  the  chimney,  just 
behind  the  mantel,  to  this  small  depth  (Rumford's  device 
for  sweeping  need  not  be  here  described).  The  sides  or 
"covings"  of  this  shallowed  recess  are  now  to  be  sloped  in- 
wards so  that  each  one  shall  horizontally  be  at  an  angle  of 
135  deg.  to  the  plane  of  this  new  back,  and  meet  it  at  a 
distance  of  six  or  more  inches  apart,  according  to  the  size 
of  grate  required.  The  covings  will  thus  spread  out  at 
right  angles  with  each  other,  and  leave  an  annular  opening 
to  be  lined  with  fire-brick,  and  run  straight  up  to  the 
chimney.  The  fire-bars  and  grate-bottom  to  be  simply  let 
into  this  as  far  forward  as  possible. 

By  this  simple  arrangement  we  get  a  fire-grate  with  a 
narrow  flat  back  and  out-sloping  sides  ;  all  these  three  walls 
are  of  fire-brick ;  the  back  radiates  perpendicularly  across 
the  room ;  and  the  sloping  sides  radiate  outwards,  instead 
of  merely  across  the  fire  from  one  to  the  other,  as  when 
they  are  square  to  the  walls. 

At  Rumford's  time  our  ordinary  fireplaces  were  square 
recesses ;  now  we  have  adopted  something  like  his  sugges- 
tion in  the  sloping  sides  of  our  register  grates,  and  we  bring 
our  fireplaces  forward.  We  have  gone  backwards  in 
material,  by  using  iron,  but  this,  after  all,  may  be  merely 
due  to  the  ironmongery  interest  overpowering  that  of  the 
bricklayers.  The  preponderance  of  this  interest  in  the 
South  Kensington  Exhibition  may  account  for  the  fact 
that  Rumford's  simple  device  was  not  to  be  seen  in  action 
there.  It  could  not  pay  anybody  to  exhibit  such  a  thing, 
as  nobody  can  patent  it,  and  nobody  can  sell  it.  I  have 
seen  the  Rumford  arrangement  carried  out  in  office  fire- 
places with  remarkable  success.  To  apply  it  anywhere  re- 
quires only  an  intelligent  bricklayer,  a  few  bricks,  and  sonic 
iron  bars. 

Although  nobody  exhibited  this,  a  very  near  approach  to 
it  was  described  in  an  admirable  lecture  delivered  at  South 
Kensington,  by  Mr.  Fletcher,  of  Warrington.  In  one  re- 
spect Mr.  Fletcher  goes  further  than  Count  Rumford  in  the 
application  of  fire-clay.  He  makes  the  bottom  of  the  fire- 
box of  a  slab  of  fire-clay  instead  of  ordinary  iron  fire-bars. 


316  SCIENCE  IN  SHORT  CHAPTERS. 

This  demands  a  little  more  trouble  and  care  in  lighting  the 
fire,  owing  to  the  absence  of  bottom-draught,  but  when 
the  fire  is  well  started  the  advantages  of  this  further  encas- 
ing in  fire-clay  are  considerable.  They  depend  upon  another 
effect  of  the  superior  radiant  and  absorbent  properties  of 
fire-clay  that  I  will  now  explain. 

So  far,  I  have  only  described  the  beneficial  effect  of  its 
radiation  on  the  room  to  be  heated,  but  it  performs  a  further 
duty  inside  the  fireplace  itself.  Being  a  bad  conductor,  it 
does  not  readily  carry  away  the  heat  of  the  burning  coal 
that  rests  upon  it,  and  being  also  an  excellent  absorber,  it 
soon  becomes  very  hot — i.e.,  superficially  hot,  or  hot  where 
its  heat  is  effective.  This  action  may  be  seen  in  a  common 
register  stove  with  fire-clay  back  and  iron  sides.  "When  the 
fire  is  brisk  the  back  is  visibly  red-hot,  while  the  sides  are 
still  dull.  If,  after  such  a  fire  has  burnt  itself  out,  we  care- 
fully examine  the  ashes,  there  will  be  found  more  fine  dust 
in  contact  with  the  fire-brick  than  with  the  iron — i.e.,  evi- 
dence of  more  complete  combustion  there ;  and  one  of  the 
advantages  justly  claimed  by  Mr.  Fletcher  is,  that  with  his 
solid  fire-clay  bottom  there  will  be  no  unburnt  cinders — 
nothing  left  but  the  incombustible  mineral  ash  of  the  coal. 
Economy  and  abatement  of  smoke  are  the  necessary  con- 
comitants of  such  complete  combustion. 

A  valuable  "wrinkle"  was  communicated  by  Mr.  Flet- 
cher. The  powdered  fire-clay  that  is  ordinarily  sold  is  not 
easily  applied  on  account  of  its  tendency  to  crumble  and 
peel  off  the  back  and  sides  of  the  stove  after  the  first  heat- 
ing. In  order  to  overcome  this,  and  obtain  a  fine  compact 
lining,  Mr.  Fletcher  recommends  the  mixing  of  the  fire- 
clay powder  with  a  solution  of  water-glass  (silicate  of  soda) 
instead  of  simple  water.  It  acts  by  forming  a  small  quan- 
tity of  glassy  silicate  of  alumina,  which  binds  the  whole  of 
the  clay  together  by  its  fusion  when  heated. 

Londoners,  and,  in  fact,  Englishmen  generally,  have  hith- 
erto regarded  anthracite  as  a  museum  mineral  'and  a  curi- 
psity,  rather  than  an  everyday  coal-scuttle  commodity.  If 
it  is  to  be  the  fuel  of  the  future,  it  is  very  desirable  that  we 
should  all  know  something  about  its  merits  and  demerits, 
as  well  as  the  possibilities  of  supply. 


FIRE-CLAY  AND  ANTHRACITE.  317 

Anthracite  is  a  natural  coke.  From  its  position  in  the 
earth,  and  its  relations  to  bituminous  coal,  as  well  as  from 
its  composition,  we  are  justified  in  regarding  it  as  a  coal 
that  was  originally  bituminous,  but  which  has  been  altered 
by  heat,  acting  under  great  pressure.  In  the  great  coal- 
field of  South  Wales,  to  which  we  must  look  for  our  main 
supply  of  anthracite,  we  are  able  to  trace  the  action  of  heat 
in  producing  a  whole  series  of  different  classes  of  coal  in  a 
single  seam,  which  at  one  part  is  highly  bituminous — soft, 
flaming  coal,  like  the  Wallsend,  then  it  becomes  harder  and 
less  bituminous,  then  semi-bituminous  "stenm  coal,"  then 
less  and  less  flaming,  until  at  last  we  have  the  hard,  shiny 
form  of  purely  carbonaceous  coal,  that  may  be  handled 
without  soiling  the  fingers,  and  which  burns  without  flame, 
like  coke  or  charcoal.  This  change  proceeds  as  the  seam 
extends  from  the  east  towards  the  west.  In  some  places 
the  coal  at  the  base  of  a  hill  may  be  anthracite,  while  that 
en  the  outcrop  above  it  may  be  bituminous. 

An  artificial  anthracite  may  be  made  by  heating  coal  in 
a  closed  vessel  of  sufficient  strength  to  resist  the  expan- 
sion of  the  gases  that  are  formed.  It  differs  from  coke  in 
being  compact,  is  not  porous,  and  therefore,  of  course, 
much  denser,  a  given  weight  occupying  less  space. 

That  we  Englishmen  should  be  about  the  last  of  all  the 
coal-using  peoples  to  apply  anthracite  to  domestic  purposes 
is  a  very  curious  fact,  but  so  it  is.  In  America  it  is  the 
ordinary  fuel,  and  this  is  the  case  in  all  other  countries 
where  it  is  obtainable  at  the  price  of  bituminous  coal.  Our 
perversity  in  this  respect  shows  out  the  more  strikingly 
when  we  go  a  little  further  into  the  subject  by  comparing 
the  two  classes  of  coal  in  reference  to  our  methods  of  using 
them,  and  when  we  consider  the  fact  that  our  South  Wales 
anthracite  is  far  superior  to  the  American. 

Our  open  fires  only  do  their  small  fraction  of  useful  work 
by  radiation.  Their  convection  is  all  up  the  chimney. 
Such  being  the  case,  and  we  being  theoretically  regarded  as 
rational  beings,  it  might  be  supposed  that  for  our  national 
and  especially  radiating  fireplaces  we  should  have  selected 
a  coal  of  especial  radiating  efficiency,  but,  instead  of  this, 
we  do  the  opposite.  The  flaming  coal  is  just  that  which 


318  SCIENCE  IN  SHORT  CHAPTERS. 

flings  the  most  heat  up  the  chimney,  and  the  least  into  the 
room,  and,  as  though  we  were  all  struggling  to  destroy  as 
speedily  as  possible  the  supposed  physical  basis  of  our  pros- 
perity, we  select  that  coal  which  in  our  particular  fire-places 
burns  the  most  wastefully.  If  we  had  closed  iron  stoves 
with  long  stove-pipes  in  the  room,  giving  to  the  air  the 
heat  they  had  obtained  by  the  convective  action  of  the  flame 
and  smoke,  there  might  be  some  reason  for  using  the  flam- 
ing coal,  as  the  flame  would  thereby  do  useful  work,  but, 
as  it  is,  we  stubbornly  persist  in  using  only  the  radiated 
heat,  and  at  the  same  time  select  just  the  coal  which  sup- 
plies the  smallest  quantity  of  what  we  require. 

No  scientific  dissertation  is  necessary  to  prove  the  supe- 
rior radiating  power  of  an  anthracite  fire  to  anybody  who 
has  ever  stood  in  the  front  of  one.  This  is  most  strik- 
ingly demonstrated  by  those  grates  that  stand  well  for- 
ward, and  are  kept  automatically  filled  with  the  radiant- 
carbon. 

Let  us  now  see  why  anthracite  is  a  better  radiator  than 
bituminous  coal.  This  is  due  to  its  chemical  composition. 
Of  all  the  substances  that  we  have  upon  the  earth  carbon 
in  its  ordinary  black  form  is  the  best  radiator.  Anthracite 
contains  from  90  to  94  per  cent  of  pure  carbon,  bituminous 
coal  from  70  to  85,  and  much  of  this  being  combined  with 
hydrogen  burns  away  as  flame.  On  a  rough  average  we 
may  say  that  the  fixed  or  solid  carbon  capable  of  burning 
with  a  smokeless  flameless  glow,  amounts  to  65  per  cent  in 
ordinary  British  bituminous  coal,  against  an  average  of  92 
per  cent  in  British  anthracite.  The  advantages  of  anthra- 
cite as  a  fuel  for  open  radiating  grates  are  nearly  in  the 
proportion  of  these  figures.  Besides  this  it  contains  about 
half  the  quantity  of  ash.  Thus  we  see  that  from  a  purely 
selfish  point  of  view,  and  quite  irrespective  of  our  duty  to 
our  fellow-citizens  as  regards  polluting  the  atmosphere, 
anthracite  is  preferable  to  ordinary  coal  on  economical 
grounds,  supposing  we  can  obtain  it  at  the  same  price  as 
bituminous  coal,  which  is  now  the  case. 

Another  great  advantage  of  anthracite  is  its  cleanliness, 
It  may  be  picked  up  in  the  fingers  without  soiling  them, 
and  it  is  similarly  cleanly  throughout  the  house.  It  pro- 


FIRE-CLAY  AND  ANTHRACITE.  319 

duces  no  "blacks,"  no  grimy  dust,  and  if  it  were  generally 
in  use  throughout  London  one  half  of  the  house-cleaning 
would  be  saved.  White  curtains,  blinds,  etc.,  might  hang 
quite  four  times  as  long,  and  then  come  down  not  half  so 
dirty  as  now.  The  saving  in  soap  alone,  without  counting- 
labor,  would  at  once  return  a  handsome  percentage  on 
the  capital  outlay  required  for  reconstructing  all  our  fire- 
places. 

Let  us  now  look  on  the  other  side,  and  ask  what  are  the 
disadvantages  of  anthracite,  and  why  is  it  not  at  once 
adopted  by  everybody?  There  is  really  only  one  disadvan- 
tage, viz.,  the  greater  difficulty  of  starting  an  anthracite 
fire.  Practically  this  is  considerable,  seeing  that  laziness 
is  universal  and  ever  ready  to  find  excuses  when  an  innova- 
tion is  proposed  that  stands  in  its  way.  To  light  an  an- 
thracite fire  in  an  ordinary  fireplace  the  bellows  are  required 
unless  a  specially  suitable  draught  or  fire-lighter  is  used. 
Some  recommend  that  an  admixture  of  bituminous  coal 
should  be  used  to  start  it,  but  this  is  a  feeble  device  calcu- 
lated to  lead  to  total  failure,  seeing  that  the  sole  originator 
and  sustainer  of  our  ordinary  use  of  bituminous  coal  is  do- 
mestic ignorance  and  indolence,  and  if  both  kinds  of  coal 
are  kept  in  a  house  a  common  English  servant  will  stub- 
bornly use  the  easy-lighting  kind,  and  solemnly  assert  that 
the  other  cannot  be  used  at  all.  The  only  way  to  deal  with 
this  obstacle,  the  human  impediment,  is  to  say,  "  This  you 
must  use,  or  go."  This  is  strictly  just,  as  a  simple  enforce- 
ment of  duty. 

At  the  same  time  some  help  should  be  supplied  in  the 
way  of  artificial  modes  of  creating  a  draught  in  starting  an 
anthracite  fire.  This  may  be  done  by  temporarily  closing 
the  front  of  the  fire  by  a  "blower,"  or  better  still  by  select- 
ing one  of  the  grates  specially  devised  for  burning  anthra- 
cite, of  which  so  many  now  are  made.  Another  and  rather 
important  matter  is  to  obtain  the  anthracite  in  suitable 
condition.  It  is  a  very  hard  coal,  too  hard  to  be  broken 
by  the  means  usually  at  hand  in  ordinary  houses.  For  do- 
mestic purposes  it  should  always  be  delivered  broken  up  of 
suitable  size,  from  that  of  an  egg  to  a  cocoa-nut.  For  fur- 
naces, of  course,  large  lumps  are  preferable. 


320  SCIENCE  IN  SHORT  CHAPTERS. 

Then,  again,  anthracite  must  not  be  stirred  and  poked 
about;  once  fairly  started  it  burns  steadily  and  brightly, 
demanding  only  a  steady  feeding.  The  best  of  the  special 
grates  are  more  or  less  automatic  in  the  matter  of  feeding, 
and  thus  the  trouble  of  lighting  is  fully  compensated  by 
the  absence  of  any  further  trouble. 

As  regards  the  supply.  This  for  London  and  the  greater 
part  of  England  will  doubtless  be  derived  'from  the  great 
coal-field  of  South  Wales.  The  total  quantity  of  available 
coal  in  this  region  after  deducting  the  waste  in  getting, 
was  estimated  bythe  Government  Commissioners  at  32,456 
millions  of  tons.  It  is  very  difficult  or  impossible  to  cor- 
rectly estimate  the  proportion  of  anthracite  in  this,  but 
supposing  it  to  be  one  tenth  of  true  anthracite  it  gives  us 
3245  millions  of  tons,  or  about  enough  for  the  domestic 
supply  of  the  whole  country  during  100  years,  assuming 
that  it  shall  be  used  less  wastefully  than  we  are  now  using 
bituminous  coal,  which  would  certainly  be  the  case.  But, 
including  the  imperfect  anthracite,  the  quantity  must  be 
far  larger  than  this,  and  we  have  to  add  the  other  sources 
of  anthracite. 

We  need  not,  therefore,  have  any  present  fear  of  insuf- 
ficient supply  ;  probably  before  the  100  years  are  ended  we 
shall  find  other  sources  of  anthracite,  or  even  have  become 
sufficiently  civilized  to  abolish  altogether  our  present  dirty 
devices,  and  to  adopt  rational  methods  of  warming  and 
ventilating  our  houses.  When  we  do  this  any  sort  of  coal 
may  be  used. 


COUNT  RUMFORD'S  COOKING-STOVES. 

IN  the  preceding  chapter  I  described  Count  Rumford's 
modification  of  the  English  open  firegrate  which  eighty 
years  ago  was  offered  to  the  British  nation  without  any 
patent  or  other  restrictions.  Its  non-adoption  I  believe  to 
be  mainly  due  to  this — it  was  nobody's  monopoly,  nobody's 
business  to  advertise  it,  and,  therefore,  nobody  took  any 


COUNT  RUMFORD'S  COOKING-STOVES.  321 

further  notice  of  it;  especially  as  it  cannot  be  made  and 
sold  as  a  separate  portable  article. 

An  ironmonger  or  stove-maker  who  should  go  to  the 
expense  of  exhibiting  Rumford's  simple  structure  of  fire- 
bricks and  a  few  bars,  described  in  the  last  chapter,  would 
be  superseding  himself  by  teaching  his  customers  how  they 
may  advantageously  do  without  him. 

The  same  remarks  apply  to  his  stoves  for  cooking  pur- 
poses. They  are  not  iron  boxes  like  our  modern  kitcheners, 
but  are  brick  structures,  matters  of  masonry  in  all  but  cer- 
tain adjuncts,  such  as  bars,  fire-doors,-  covers,  oven-boxes, 
etc.,  which  are  very  simple  and  inexpensive.  Even  some  of 
Rumford's  kitchen  utensils,  such  as  the  steamers,  were 
cheaply  covered  with  wood,  because  it  is  a  bad  conductor, 
and  therefore  wastes  less  heat  than  an  iron  saucepan  lid. 

Rumford  was' no  mere  theorist,  although  he  contributed 
largely  to  pure  science.  His  greatest  scientific  discoveries 
were  made  in  the  course  of  his  persevering  efforts  to  solve 
practical  problems.  I  must  not  be  tempted  from  my  imme- 
diate subject  by  citing  any  examples  of  these,  but  may  tell 
a  fragment  of  the  story  of  his  work  so  far  as  it  bears  upon 
the  subject  of  cooking-ranges. 

He  began  life  as  a  poor  schoolmaster  in  ]S"ew  Hamp- 
shire, when  it  was  a  British  colony.  He  next  became  a 
soldier;  then  a  diplomatist;  then  in  strange  adventurous 
fashion  he  traveled  on  the  Continent  of  Europe,  entered 
the  Bavarian  service  and  began  his  searching  reform  of  the 
Bavarian  army  by  improving  the  feeding  and  the  clothing 
of  the  men.  He  became  a  practical  working  cook  in  order 
that  they  should  be  supplied  with  good,  nutritious,  and 
cheap  food. 

But  this  was  not  all.  He  found  Munich  in  a  most  de- 
plorable condition  as  regards  mendicity;  and  took  in  hand 
the  gigantic  task  of  feeding,  clothing,  and  employing  the 
overwhelming  horde  of  paupers,  doing  this  so  effectually 
that  he  made  his  "House  of  Industry"  a  true  workhouse; 
it  paid  all  its  own  expenses,  and  at  the  end  of  six  years  left 
a  net  profit  of  100,000  florins. 

I  mention  these  facts  in  conformation  of  what  I  said 
above  concerning  his  practical  character.  Economical 


322  SCIENCE  IN  SHORT  CHAPTERS. 

cookery  was  at  the  root  of  his  success  in  this  maintenance 
of  a  workhouse  without  any  poor-rates. 

After  doing  all  this  he  came  to  England,  visited  many  of 
our  public  institutions,  reconstructed  their  fireplaces,  and 
then  cooked  dinners  in  presence  of  distinguished  witnesses, 
in  order  to  show  how  little  need  be  expended  on  fuel,  when 
it  is  properly  used. 

At  the  Foundling  Institution  in  London  he  roasted  112 
Ibs.  of  beef  with  22  Ibs.  of  coal,  or  at  a  cost  of  less  than 
threepence.  The  following  copy  of  certificate,  signed  by 
the  Councillor  of  War,  etc.,  shows  what  he  did  at  Munich  : 
"•'  We  whose  names  are  underwritten  certify  that  we  have 
been  present  frequently  when  experiments  have  been  made 
to  determine  the  expense  of  fuel  in  cooking  for  the  poor  in 
the  public  kitchen  of  the  military  workhouse  at  Munich, 
and  that  when  the  ordinary  dinner  has  been  prepared  for 
1000  persons,  the  expense  for  fuel  has  not  amounted  to 
quite  12  kreutzers."  Twelve  kreutzers  is  about  ±%d.  of  our 
money.  Thus  only  l-50th  of  a  farthing  was  expended  on 
cooking  each  person's  dinner,  although  the  peas  which 
formed  the  substantial  part  of  the  soup  required  five  hours, 
boiling.  The  whole  average  daily  fuel  expenses  of  the 
kitchen  of  the  establishment  amounted  to  l-20th  of  a 
farthing  for  each  person,  using  wood,  which  is  much  dearer 
than  coal.  At  this  rate,  one  ton  of  ivood  should  do  the  cook- 
ing for  ten  persons  during  two  years  and  six  days,  or  one 
ton  of  coal  would  supply  the  kitchen  of  such  a  family  three 
and  a  half  years. 

The  following  is  an  abstract  of  the  general  principles 
which  he  expounds  for  the  guidance  of  all  concerned  in  the 
construction  of  cooking  stoves. 

1.  All  cooking  fires  should  be  enclosed. 

2.  Air  only  to  be  admitted  from  below  and  under  com- 
pete control.    All  air  beyond  what  is  required  for  the  supply 
of  oxygen  "is  a  thief." 

3.  All  fireplaces  to  be  surrounded  by  non-conductors, 
Iriclcivork,  not  iron. 

4.  The  residual  heat  from  the  fireplace  to  be  utilized  by 
long  journeys  in  returning  flues,  and  by  doing  the  hottest 
u' or  k  first. 


COUNT  RUMFORD'S  COOKING-STOVES.          323 

5.  Different  fires  should  be  used  for  different  work. 

The  first  of  these  requirements  encounters  one  of  our 
dogged  insular  prejudices.  The  slaves  to  these  firmly 
believe  that  meat  can  only  be  roasted  by  hanging  it  up  to 
dry  in  front  of  an  open  fire  ;  their  savage  ancestors  having 
held  their  meat  on  a  skewer  or  spit  over  or  before  an  open 
fire,  modern  science  must  not  dare  to  demonstrate  the 
wasteful  folly  of  the  holy  sacrifice.  Their  grandmothers 
having  sent  joints  to  a  bakehouse,  where  other  people  did 
the  same,  and  having  found  that  by  thus  cooking  beef, 
mutton,  pork,  geese,  etc.,  some  fresh,  and  some«stale,  in  the 
same  oven,  the  flavors  became  somewhat  mixed,  and  all 
influenced  by  sage  and  onions,  these  people  persist  in 
believing  that  meat  cannot  be  roasted  in  any  kind  of  closed 
chamber. 

Rumford  proved  the  contrary,  and  everybody  who  has 
fairly  tried  the  experiment  knows  that  a  properly  ventilated 
and  properly  heated  roasting  oven  produces  an  incompara- 
bly better  result  than  the  old  desiccating  process. 

Rumford's  roaster  was  a  very  remarkable  contrivance, 
that  seems  to  have  been  forgotten.  It  probably  demands 
more  intelligence  in  using  it  than  is  obtainable  in  a  present- 
day  kitchen.  When  the  School  Boards  have  supplied  a 
better  generation  of  domestic  servants  we  may  be  able  to 
restore  its  use. 

It  is  a  cylindrical  oven  with  a  double  door  to  prevent  loss 
of  heat.  In  this  the  meat  rests  on  a  grating  over  a  specially 
constructed  gravy  and  water  dish.  Under  the  oven  are  two 
"Wow-pipes,"  i.e.,  stout  tubes  standing  just  above  the  fire 
so  as  to  be  made  red  hot,  and  opening  into  the  oven  at  the 
back,  and  above  the  fircpla.ce  in  front,  where  there  is  a  plug 
to  be  closed  or  open  as  required.  Over  the  front  part  of  the 
top  of  the  oven  is  another  pipe  for  carrying  away  the  vapor. 
It  is  thus  used  :  The  meat  is  first  cooked  in  an  atmosphere 
of  steam  formed  by  the  boiling  of  water  placed  in  the  bot- 
tom of  the  double  dish,  over  which  the  meat  rests.  When 
by  this  means  the  meat  has  been  raised  throughout  its  whole 
thickness  to  the  temperature  at  which  its  albumen  coagu- 
lates, the  plugs  are  removed  from  the  blow-pipes,  and  then 
the  special  action  of  roasting  commences  by  the  action  of  a 


324  SCIENCE  IN  SHORT  CHAPTERS. 

current  of  superheated  air  which  enters  below  and  at  the 
back  of  the  oven,  travels  along  and  finds  exit  above  and  in 
front  of  the  steam-pipe  before  named. 

The  result  is  a  practical  attainment  of  theoretical  perfec- 
tion. Instead  of  the  joint  being  dried  and  corticated  out- 
side, made  tough,  leathery,  and  flavorless  to  about  an  inch 
of  depth,  then  fairly  cooked  an  inch  further,  and  finally 
left  raw,  disgusting,  and  bloody  in  the  middle,  as  it  is  in 
the  orthodox  roasting  by  British  cooks,  the  whole  is  uni- 
formly cooked  throughout  without  the  soddening  action  of 
mere  boiling  or  steaming,  as  the  excess  of  moisture  is  re- 
moved by  the  final  current  of  hot  dry  air  thrown  in  by  the 
blow-pipes,  which  at  the  same  time  give  the  whole  surface 
an  uniform  browning  that  can  be  regulated  at  will  without 
burning  any  portion  or  wasting  the  external  fat. 

Eumford's  second  rule,  that  air  be  admitted  only  from 
below,  and  be  limited  to  the  requirements,  is  so  simple  that 
no  comment  upon  it  is  needed.  Although  we  have  done  so 
little  in  the  improvement  of  domestic  fireplaces,  great  pro- 
gress has  been  made  in  engine  furnaces,  blast  furnaces,  and 
all  other  fireplaces  for  engineering  and  manufacturing  pur- 
poses. Every  furnace  engineer  now  fully  appreciates  Rum- 
ford's  assertion  that  excess  of  cold  air  is  a  thief. 

The  third  rule  is  one  which,  as  I  have  already  stated, 
stands  seriously  in  the  way  of  any  commercial  "pushing" 
of  Eumford's  kitchen  ranges.  Those  which  he  figures  and 
describes  are  all  of  them  masonic  structures,  not  iron- 
mongery; the  builder  must  erect  them,  they  cannot  be 
bought  ready-made ;  but,  now  that  public  attention  is 
roused,  I  believe  that  any  builder  who  will  study  Eum- 
ford's plans  and  drawings,  which  are  very  practically  made, 
may  do  good  service  to  himself 'and  his  customers  by  fitting 
up  a  few  houses  with  true  Eumford  kitcheners,  and  offer- 
ing to  reconstruct  existing  kitchen  ranges,  especially  in  large 
houses. 

The  fourth  rule  is  one  that  is  sorely  violated  in  the  ma- 
jority of  kitcheners,  and  without  any  good  reason.  The 
heat  from  the  fire  of  any  kitchener,  whether  it  be  of  brick 
or  iron,  should  first  do  the  work  demanding  the  highest 
temperature,  viz.,  roasting  and  baking,  then  proceed  to  the 


COUNT  MUMF01W8  COOKING-STOVES.  325 

boiler  or  boilers,  and  after  this  be  used  for  supplying  the 
bed-rooms  and  bath-room,  and  the  housemaid,  etc.,  with 
hot  water  for  general  use,  as  Kumford  did  in  his  house  at 
Brompton  Row,  where  his  chimney  terminated  in  metal 
pipes  that  passed  through  a  water-tank  at  the  top  of  the 
house. 

Linen-closets  may  also  be  warmed  by  this  residual  heat. 

The  fifth  rule  is  also  violated  to  an  extent  that  renders 
the  words  uttered  by  Rumford  nearly  a  century  ago  as  ap- 
plicable now  as  then.  He  said,  "Nothing  is  so  ill-judged 
as  most  of  those  attempts  that  are  frequently  made  by  ig- 
norant projectors  to  force  the  same  fire  to  perform  different 
services  at  the  same  time." 

Note  the  last  words,  "same  time."  In  the  uses  above 
mentioned  the  heat  does  different  work  successively,  which 
is  quite  different  from  the  common  practice  of  having  flues 
to  .turn  the  flame  of  one  fire  in  opposite  directions,  to  split 
ks  heat  and  make  one  fireplace  appear  to  do  the  work  of 
two. 

Every  householder  knows  that  the  kitchen  fire,  whether 
it  be  an  old-fashioned  open  fireplace,  or  a  modern  kitchener 
of  any  improved  construction,  is  a  very  costly  affair.  He 
knows  that  its  wasteful  work  produces  the  chief  item  of  his 
coal  bill,  but  somehow  or  other  he  is  helpless  under  its  in- 
fliction. If  he  has  given  any  special  attention  to  the  sub- 
ject he  has  probably  tried  three  or  four  different  kinds  with- 
out finding  any  notable  relief.  Why  is  this?  I  venture  to 
make  a  reply  that  will  cover  90  per  cent,  or  probably  99 
per  cent  of  these  cases,  viz.,  that  he  has  never  considered 
the  main  source  of  waste,  which  Rumford  so  clearly  defines 
as  above,  and  which  was  eliminated  in  all  the  kitchens  that 
he  erected. 

Let  us  suppose  the  case  of  a  household  of  ten  persons, 
but  which  in  the  ordinary  course  of  English  hospitality 
sometimes  entertains  twice  that  number.  What  do  we  find 
in  the  kitchen  arrangements?  Simply  that  there  is  oi:e 
fireplace  suited  for  the  maximum  requirements,  i.e.,  suffi- 
cient for  twenty,  even  though  that  number  may  not  be  en- 
tertained more  than  half  a  dozen  times  in  the  course  of  a 
year.  To  cook  a  few  rashers  of  bacon,  boil  a  few  eggs,  and 


326  SCIENCE  IN  SHORT  CHAPTERS. 

boil  a  kettle  of  water  for  breakfast,  a  fire  sufficient  to  cook 
for  a  dinner  party  of  twenty  is  at  work.  This  is  kept  on 
all  day  long,  because  it  is  just  possible  that  the  master  of 
the  house  may  require  a  glass  of  grog  at  bedtime.  There 
may  be  dampers  and  other  devices  for  regulating  this  fire, 
but  such  regulation,  even  if  applied,  does  very  little  so  long- 
as  the  capacity  of  the  grate  remains,  and  as  a  matter  of  or- 
dinary facl;  the  dampers  and  other  regulating  devices  arc 
neglected  altogether;  the  kitchen  fire  is  blazing  and  roar- 
ing to  waste  from  6  or  7  A.  M.  to  about  midnight,  in  order 
to  do  about  three  hours  and  a  half  work,  i.e.,  the  dinner 
for  ten,  and  a  nominal  trifle  for  the  other  meals. 

In  Eumford's  kitchens,  such  as  those  he  built  for  the 
Baron  de  Lerchenfeld  and  for  the  House  of  Industry  at 
Munich,  the  kitchener  is  a  solid  block  of  masonry  of 
work-bench  height  at  top,  and  with  a  deep  bay  in  the 
middle,  wherein  the  cook  stands  surrounded  by  his  boilers, 
steamers,  roasters,  ovens,  etc.,  all  within  easy  reach,  each 
one  supplied  by  its  own  separate  fire  of  very  small  di- 
mensions, and  carefully  closed  with  non-conducting  doors. 
Each  fire  is  lighted  when  required,  charged  with  only  the 
quantity  of  fuel  necessary  for  the  work  to  be  done,  and 
then  extinguished  or  allowed  to  die  out. 

It  is  true  that  Kumford  used  wood,  which  is  more  easily 
managed  in  this  way  than  coal.  If  we  worked  as  he  did, 
we  might  use  wood  likewise,  and  in  spite  of  its  very  much 
higher  price  do  our  cooking  at  half  its  present  cost.  This 
would  effect  not  merely  "smoke  abatement"  but  "smoke 
extinction"  so  far  as  cooking  is  concerned.  But  the  light- 
ing of  fires  is  no  longer  a  troublesome  and  costly  process 
as  in  the  days  of  halfpenny  bundles  of  firewood.  To  say 
nothing  of  the  improved  fire-lighters,  we  have  gas  every- 
where, and  nothing  is  easier  than  to  fix  or  place  a  suitable 
Bunsen  or  solid  flame  burner  under  each  of  the  fireplaces 
(an  iron  gaspipe,  perforated  below  to  avoid  clogging,  will 
do),  and  in  two  or  three  minutes  the  coals  are  in  full  blaze  ; 
then  the  gas  may  be  turned  off.  The  writer  has  used  such 
an  arrangement  in  his  study  for  some  years  past,  and  starts 
his  fire  in  full  blaze  in  three  minutes  quite  independent  of 
all  female  interference. 


THE  "CONSUMPTION  OF  SMOKE."  327 

I  have  no  doubt  that  ultimately  gas  will  altogether  su- 
persede coal  for  cooking ;  but  this  and  all  other  scientific 
improvements  in  domestic  comfort  and  economy  must  be 
impossible  with  the  present  generation  of  uneducated  do- 
mestics, whose  brains  (with  few  exceptions)  have  become 
torpid  and  wooden  from  lack  of  systematic  exercise  during 
their  period  of  growth. 


THE  "  CONSUMPTION  OF  SMOKE." 

A  GREAT  deal  has  been  spoken  and  written  on  this  sub- 
ject, but  practically  nothing  has  been  done  At  one  time 
I  shared  the  general  belief  in  its  possibility,  and  accord- 
ingly examined  a  multitude  of  devices  for  smoke-consum- 
ing, and  tried  several  of  the  most  promising,  chiefly  in 
furnaces  for  metallurgical  work,  for  steam  boilers  and  stills. 
None  of  them  proved  satisfactory,  and  I  was  driven  to  the 
conclusion  that  smoke-consumption  is  a  delusion,  and  fur- 
ther, that  economical  consumption  of  smoke  is  practically 
impossible.  When  smoke  is  once  formed,  the  cost  of  burn- 
ing it  far  exceeds  the  value  of  the  heat  that  is  produced  by 
the  combustion  of  its  very  flimsy  flocculi  of  carbon.  It  is 
a  fiend  that  once  raised  cannot  be  exorcised,  a  Frankenstein 
that  haunts  its  maker,  and  will  not  be  appeased. 

To  describe  in  detail  the  many  ingenious  devices  that 
have  been  proposed  and  expensively  patented  and  adver- 
tised for  this  object,  would  carry  me  far  beyond  the  in- 
tended limits  of  this  paper.  I  must  not  even  attempt  this 
for  a  selected  few,  as  even  among  them  there  is  none  that 
can  be  pronounced  satisfactory. 

The  common  idea  is  that  if  the  smoke  be  carried  back  to 
the  fire  that  produced  it,  and  made  to  pass  through  it 
again,  a  recombustion  or  consumption  of  the  smoke  will 
take  place.  This  is  a  mistake,  as  a  little  reflection  will 
show.  First,  let  us  ask  why  did  this  particular  fire  pro- 
duce such  smoke?  Everybody  now-a-days  can  answer  this 
question,  as  we  all  know  that  smoke  is  a  result  of  imper- 


328  SCIENCE  IN  SHORT  CHAPTERS. 

feet  combustion,  and,  knowing  this,  it  can  easily  be  under- 
stood that  to  return  the  carbonic  acid  and  excess  of  carbon 
to  the  already  suffocated  fire  can  only  add  smother  to  smoth- 
eratioii,  and"make  the  smoky  fire  more  smoky  still. 

There  is,  however,  one  case  in  which  a  lire  appears  to 
thus  consume  its  own  smoke,  but  the  appearance  is  delu- 
sive. I  refer  to  fires  lighted  from  above.  These,  if  pro- 
perly managed,  are  practically  smokeless,  and  it  is  com- 
monly supposed  that  smoke  passes  from  the  raw  coal  below 
through  the  burning  coal  above,  and  is  thereby  consumed. 
The  fact  is,  however,  that  no  such  smoke  is  formed.  That 
which  under  these  conditions  comes  from  the  coal  beneath, 
when  gradually  heated  by  the  fire  above,  is  combustible  gas, 
and  this  gas  is  burned  as  it  passes  through  the  fire.  In 
this  case  the  formation  or  non-formation  of  smoke  depends 
mainly  on  how  this  gas  is  burned,  whethey  completely  or 
incompletely.  If  the  air  supplied  for  its  combustion  is  in- 
sufficient, smoke  will  be  formed  as  it  is  when  we  turn  up 
an  Argand  gas-flame  so  high  that  the  gas  is  too  great  in 
proportion  to  the  quantity  of  air  that  can  enter  the  glass 
chimney. 

Herein  lies  the  fundamental  principle.  We  may  prevent 
smoke,  though  we  cannot  cure  it,  and  this  prevention  de- 
pends upon  how  \ve  supply  air  to  the  gas  which  the  coal 
gives  off  when  heated,  and  upon  the  condition  of  this  gas 
when  we  bring  it  in  contact  with  the  air  by  which  its  com- 
bustion is  to  be  effected.  We  must  always  remember  that 
coal  when  its  temperature  is  sufficiently  heated,  whether  in 
a  gas  retort  or  fireplace,  gives  off  a  series  of  combustible 
hydrocarbon  gases  and  vapors,  and  all  we  have  to  do  in  or- 
der to  obtain  smokeless  fires  is  to  secure  the  complete  com- 
bustion of  these. 

Now  we  know  that  to  burn  a  given  quantity  of  gas  we 
must  supply  it  with  a  sufficient  quantity  of  oxygen,  i.e.,  of 
the  active  principle  of  the  air;  but  this  is  not  all:  we  all 
know  well  enough  that  if  cold  coal-gas  and  cold  air  be 
brought  together  in  any  proportion  whatever  no  combustion 
occurs.  A  certain  amount  of  heat  is  necessary  to  start  the 
chemical  combination  of  oxygen  with  hydrogen  and  carbon, 
which  combination  i.s  the  combustion,  or  burning. 


THE  "VOSHUXPTWN  OF  -SMOKE."  329 

Therefore,  when  the  coal  gas  and  the  air  are  brought  to> 
getlier  oneja  the  other,  or  both,  must  be  heated  up  to  a 
certain  point  in  order  that  the  combustion  be  complete.  If 
cold  there  is  no  combustion;  if  insufficiently  heated,  there 
is  imperfect  combustion,  however  well  the  supplies  may  be 
regulated. 

A  very  simple  experiment  that  anybody  may  make  illus- 
trates this.  When  an  ordinary  open  fire  is  burning  brightly 
and  clearly  without  flame,  throw  a  few  small  pieces  of  raw 
coal  into  the  midst  of  the  glowing  coals.  They  will  flame 
fiercely,  but  without  smoking.  Then  throw  a  heap  of  coal 
or  one  large  lump  on  a  similar  fire.  Now  you  will  have 
dense  volumes  of  smoke,  and  little  or  no  flame,  simply  be- 
cause the  cooling  action  of  the  large  bulk  of  coal  in  the 
course  of  distillation  brings  the  temperature  of  its  gases 
below  that  required  for  their  complete  combustion. 

This  simple  experiment  supplies  a  most  important  prac- 
tical lesson,  as  well  as  a  philosophical  example.  The  best 
of  all  smoke-abatement  machines  is  an  intelligent  and  con- 
scientious stoker,  and  every  contrivance  for  smoke  abate- 
ment must,  in  order  to  be  efficient,  either  be  fed  by  such  a 
stoker  or  provided  with  some  automatic  arrangement  by 
which  the  apparatus  itself  does  the  work  of  such  a  stoker 
by  supplying  the  fresh  fuel  just  when  and  where  it  is 
wanted. 

Cornish  experience  is  very  instructive  in  this  respect. 
The  engines  that  pump  the  water  from  the  mines  do  a 
definitely  measurable  amount  of  work,  and  are  made  to 
register  this.  The  stoker  is  a  skilled  workman,  and  prizes 
are  given  to  thoso  who  obtain  the  largest  amount  of ."  duty" 
from  given  engines  per  ton  of  coal  consumed.  Instead  of 
pitching  his  coal  in  anyhow,  cramming  his  fire-hole,  and 
then  sitting  down  to  sleep  or  smoke  in  company  with  his 
chimney,  the  Cornish,  or  other  good  fireman,  feeds  little 
and  often,  and  deftly  sprinkles  the  contents  of  his  shovel 
just  where  the  fire  is  the  brightest  and  the  hottest,  and 
the  bars  are  the  least  thickly  covered.  The  result  is  re- 
markable. A  colliery  proprietor  of  South  Staffordshire 
was  visiting  Cornwall,  and  went  with  »  friend  to  see  his 
works.  On  approaching  the  engine-house  and  seeing  a 


380  SCIENCE  IN  SHORT  CHAPTERS. 

whitewashed  shaft  with  no  smoke  issuing  from  its  mouth, 
he  expressed  his  disappointment  at  finding  that  the  engine 
was  not  at  work.  To  all  who  have  been  accustomed 
to  the  "Black  Country,"  where  coal  is  so  shamefully 
wasted  because  it  is  cheap,  the  tall  clean  whitewashed 
shafts  of  Cornwall,  all  so  smokeless,  present  quite  an  as- 
tonishing appearance. 

This  is  not  a  result  of  "  smoke-consuming"  apparatus, 
but  mainly  of  careful  firing.  It  was  in  the  first  place  pro- 
moted by  the  high  price  of  coal  due  to  the  cost  of  carriage 
before  the  Cornish  railways  were  constructed,  and  it  brought 
about  a  curious  result.  Horse-power  for  horse-power  the 
cost  of  fuel  for  working  Cornish  pumping  engines  has  been 
brought  below  that  of  pumping  engines  in  the  places  where 
the  price  of  coal  per  ton  was  less  than  one-half.  Another 
coal  famine  that  should  raise  the  price  of  coal  in  London 
to  60s.  per  ton,  and  keep  it  there  for  two  or  three  years, 
would  effect  more  smoke  abatement  than  we  can  hope  to 
result  from  the  present  and  many  future  South  Kensing- 
ton efforts.  I  need  scarcely  dwell  upon  the  necessity  for 
a  due  supply  of  air.  T^his  is  well  understood  by  everybody. 
An  over  supply  of  air  does  mischief,  by  carrying  away 
wastefully  a  proportionate  quantity  of  heat.  The  waste 
due  to  this  is  sometimes  very  serious. 

After  reviewing  all  that  has  been  done,  the  conclusion 
that  London  cannot  become  a  clean,  smokeless,  and  beauti- 
ful city,  so  long  as  we  are  dependent  upon  open  fire-grates 
of  anything  like  ordinary  construction,  and  fed  with  bitu- 
minous coal,  is  inevitable.  The  general  use  of  anthracite 
would  effect  the  desired  change,  but  there  is  no  hope  of  its 
becoming  general  without  legislative  compulsion,  and  Eng- 
lishmen will  not  submit  to  this. 

One  of  the  most  hopeful  schemes  is  that  which  was  pro- 
pounded a  short  time  since  by  Mr.  Scott  Moncrieff.  Instead 
of  receiving  our  coal  in  its  crude  state  he  proposes  that  wo 
should  have  its  smoke-producing  constituents  removed  be- 
fore it  is  delivered  to  us;  that  it  should  be  made  into  a  sort 
of  artificial  semi-anthracite  at  the  gas-works  by  a  process  of 
half  distillation,  which  would  take  away  not  all  the  flaming 
gas  as  at  present,  but  that  portion  which  is  by  far  the  rich- 


THE  "CONSUMPTION  OF  SMOKE."  331 

est  to  the  gas-maker  and  the  most  unmanageable  in  com- 
mon fires.  We  should  thus  have  a  material  which,  instead 
of  being  so  difficult  to  light  as  coke  and  anthracite,  would 
light  more  easily  than  crude  coal,  and  at  the  same  time  our 
gas  would  have  far  greater  illuminating  power,  as  it  would 
all  be  drawn  off  during  the  early  period  of  distillation,  when 
it  is  at  its  richest.  From  a  given  quality  of  coal  the  dif- 
ference would  be  as  twenty-four  candles  to  sixteen.  The 
ammonia  which  we  now  throw  into  the  air,  the  naphtha  and 
coal-tar  products,  which  we  waste,  are  so  valuable  that 
they  would  pay  all  the  expenses  at  the  gas-works  and  leave 
a  handsome  profit.  We  should  thus  get  gas  so  much  better 
that  two  burners  would  do  the  work  now  obtained  from 
three.  We  should  get  all  we  require  for  lighting  purposes 
and  plenty  more  for  heating;  the  intermediate  profits  of 
the  coal  merchant  would  be  abolished,  and  our  solid  fuel 
of  far  better  quality  could  be  supplied  twenty  or  thirty  per 
cent  cheaper  than  at  present,  provided  always  that  the  gas 
monopoly  were  abolished,  "a  consummation  most  devoutly 
to  be  wished  for." 

Mr.  Moncrieff  (who  brought  forward  his  scheme  without 
any  company-mongering,  or  claims  for  patent  rights)  esti- 
mates the  saving  to  London  at  £2, 125, 000  per  annum,  over 
and  above  the  far  greater  saving  that  would  result  from  the 
abolition  of  smoke. 

In  connection  with  this  scheme  I  may  mention  a  fact 
that  has  not  been  hitherto  noted,  viz.,  that  we  have  per- 
force and  unconsciously  done  a  little  in  this  direction  al- 
ready. Formerly  London  was  supplied  almost  exclusively 
with*  "  Wallsend"  and  other  sea-borne  coals  of  a  highly  bi"- 
tuminous  composition — soft  coals  that  fused  in  the  grate 
and  caked  together.  Partly  owing  to  exhaustion  of  the 
seams,  and  partly  to  the  competition  of  railway  transit,  we 
now  obtain  a  large  proportion  of  hard  coal  from  the  Mid- 
lands. This  is  -less  smoky  and  less  sooty,  and  hence  the 
Metropolitan  smoke  nuisance  has  not  increased  quite  as 
greatly  as  the  population. 

But  I  will  now  conclude  by  repeating  that  whatever 
scheme  be' chosen,  "smoke  abatement"  is  to  be  achieved, 
not  by  smoke-consumption,  but  by  smoke-prevention. 


332  SCIENCE  IN  SHORT  CHAPTERS. 


THE  AIR  OF  STOVE-HEATED  ROOMS. 

WHATEVER  opinions  may  be  formed  of  the  merits  of  the 
exhibits  at  South  Kensington,  one  result  is  unquestionable 
— the  exhibition  itself  has  done  much  in  directing  public 
attention  to  the  very  important  subject  of  economizing  fuel 
and  the  diminution  of  smoke.  We  sorely  need  some  les- 
sons. Our  national  progress  in  this  direction  has  been  sim- 
ply contemptible,  so  far  as  domestic  fireplaces  are  con- 
cerned. 

To  prove  this  we  need  only  turn  back  to  the  essays  of 
Benjamin  Thompson,  Count  of  Rumford,  published  in 
London  just  eighty  years  ago,  and  find  therein  nearly  all 
that  the  Smoke  Abatement  Exhibition  ought  to  teach  us, 
both  in  theory  and  practice — lessons  which  all  our  progress 
since  1802,  plus  the  best  exhibits  at  South  Kensington,  we 
have  yet  to  learn. 

This  small  progress  in  domestic  heating  is  the  more  re- 
markable when  contrasted  with  the  great  strides  we  have 
made  in  the  construction  and  working  of  engineering  and 
metallurgical  furnaces,  the  most  important  of  which  is  dis- 
played in  the  Siemens  regenerative  furnace.  A  climax  to 
this  contrast  is  afforded  by  a  speech  made  by  Dr.  Siemens 
himself,  in  which  he  defends  our  domestic  barbarisms  with 
all  the  conservative  inconvincibility  of  a  born  and  bred 
Englishman,  in  spite  of  his  German  nationality. 

The  speech  to  which  I  refer  is  reported  in  the  "  Journal 
of  the  Society  of  Arts,"  December  9,  1881,  and  contains 
some  curious  fallacies,  probably  due  to  its  extemporaneous 
character;  but  as  they  have  been  quoted  and  adopted  not 
only  in  political  and  literary  journals,  but  also  by  a  maga- 
zine of  such  high  scientific  standing  as  Nature  (see  edi- 
torial article  January  5,  1882,  p.  219),  they  are  likely  to 
mislead  many.  ' 

Having  already,  in  my  "  History  of  Modern  Invention, 
etc.,"  and  in  other  places,  expressed  my  great  respect  for 
Dr.  Siemens  and  his  benefactions  to  British  industry,  the 
spirit  in  which  the  following  plain-spoken  criticism  is  made 


THE  AIR  OF  STOVE-HEATED  ROOM8.  333 

will  not,  I  hope,  be  misunderstood  either  by  the  readers  of 
"  Knowledge"  or  by  Dr.  Siemens  himself. 

I  may  further  add  that  I  am  animated  by  a  deadly  hatred 
of  our  barbarous  practice  of  wasting  precious  coal  by  burn- 
ing it  in  iron  fire-baskets  half  buried  in  holes  within  brick 
walls,  and  under  shafts  that  carry  80  or  90  per  cent  of  its 
heat  to  the  clouds;  that  pollute  the  atmosphere  of  our 
towns,  and  make  all  their  architecture  hideous;  that  ren- 
der scientific  and  efficient  ventilation  of  our  houses  impos- 
sible; that  promote  rheumatism,  neuralgia,  chilblains, 
pulmonary  diseases,  bronchitis,  and  all  the  other  "ills  that 
flesh  is  heir  to"  when  roasted  on  one  side  and  cold-blasted 
on  the  other;  that  I  am  so  rabid  on  this  subject,  that  if 
Dr.  Siemens,  Sir  F.  Bramwell,  and  all  others  who  defend 
this  English  abomination,  were  giant  windmills  in  full  ro- 
tation, I  would  emulate  the  valor  of  my  chivalric  predeces- 
sor, whatever  might  be  the  personal  consequences. 

Dr.  Siemens  stated  that  the  open  fireplace  "  communi- 
cates absolutely  no  heat  to  the  air  of  the  room,  because  air, 
being  a  perfectly  transparent  medium,  the  rays  of  heat 
pass  clean  through  it." 

Here  is  an  initial  mistake.  It  is  true  that  air  which  has 
been  artificially  deprived  of  all  its  aqueous  vapor  is  thus 
completely  permeable  by  heat  rays,  but  such  is  far  from 
being  the  case  with  the  water  it  contains.  This  absorbs  a 
notable  amount  even  of  bright  solar  rays,  and  a  far  greater 
proportion  of  the  heat  rays  from  a  comparatively  obscure 
source,  such  as  the  red-hot  coals  and  flame  of  a  common 
fire.  Tyndall  has  proved  that  8  to  10  per  cent  of  all  the 
heat  radiating  from  such  a  source  as  a  common  fire  is  ab- 
sorbed in  passing  through  only  5  feet  of  air  in  its  ordinary 
condition,  the  variation  depending  upon  its  degree  of  satu- 
ration with  aqueous  vapor. 

Starting  with  the  erroneous  assumption  that  the  rays  of 
heat  pass  "  clean  through"  the  air  of  the  room,  Dr.  Siemens 
went  on  to  say  that  the  open  fireplace  "  gives  heat  only  by 
heating  the  walls,  ceiling,  and  furniture,  and  here  is  the 
great  advantage  of  the  open  fire;"  and,  further,  that  "if 
the  air  in  the  room  were  hotter  than  the  walls,  condensation 
would  take  place  on  them,  and  mildew  and  fermentation  of 


334  8GIENCE  IN  SHORT  CHAPTERS. 

various  kinds  would  be  engendered;  whereas,  if  the  air  were 
cooler  than  the  walls,  the  latter  must  be  absolutely  dry." 

Upon  these  assumptions,  Dr.  Siemens  condemns  steam- 
pipes  and  stoves,  hot-air  pipes,  and  all  other  methods  of, 
directly  heating  the  air  of  apartments,  and  thereby  making 
it  warmer  than  were  the  walls,  the  ceiling,  and  furniture 
when  the  process  of  warming  commenced.  It  is  quite  true 
that  stoves,  stove-pipes,  hot-air  pipes,  steam -pipes,  etc.,  do 
this;  they  raise  the  temperature  of  the  air  directly  by  con- 
vection, i.e.,  by  warming  the  film  of  air  in  contact  with 
their  surfaces,  which  film,  thus  heated  and  expanded,  rises 
towards  the  ceiling,  and,  on  its  way,  warms  the  air  around 
it,  and  then  is  followed  by  other  similarly-heated  ascending 
films.  When  we  make  a  hole  in  the  wall,  and  burn  our 
coals  within  such  cavity,  this  convection  proceeds  up  the 
chimney  in  company  with  the  smoke. 

But  is  Dr.  Siemens  right  in  saying  that  the  air  of  a  room, 
raised  by  convection  above  its  original  temperature,  and 
above  that  of  the  walls,  deposits  any  of  its  moisture  on  these 
walls?  I  have  no  hesitation  in  saying  very  positively  that 
he  is  clearly  and  demonstrably  wrong  ;  that  no  such  con- 
densation can  possibly  take  place  under  the  circumstances. 

Suppose,  for  illustration  sake,  that  we  start  with  a  room 
of  which  the  air  and  walls  are  at  the  freezing  point,  32°  F., 
before  artificial  heating  (any  other  temperature  will  do), 
and,  to  give  Dr.  Siemens  every  advantage,  we  will  further 
suppose  that  the  air  is  fully  saturated  with  aqueous  vapor, 
i.e.,  just  in  the  condition  at  which  some  of  its  water  might 
be  condensed.  Such  condensation,  however,  can  only  take 
place  by  cooling  the  air  below  32°,  and  unless  the  walls  or 
ceiling  or  furniture  are  capable  of  doing  this  they  cannot 
receive  any  moisture  due  to  such  condensation,  or,  in  other 
words,  they  must  fall  below  32°  in  order  to  obtain  it  by 
cooling  the  film  in  contact  with  them.  Of  course  Dr.  Sie- 
mens will  not  assert  that  the  stoves  or  steam-pipes  (enclos- 
ing the  steam,  of  course),  or  the  hot-air  or  hot-water  pipes, 
will  lower  the  absolute  temperature  of  the  walls  by  heating 
the  air  in  the  room. 

But  if  the  air  is  heated  more  rapidly  than  are  the  walls, 
etc.,  the  relative  temperature  of  these  will  be  lower.  Will 


THE  AIR  OF  STOVE-HEATED  ROOMS.  335 

condensation  of  moisture  then  follow,  as  Dr.  Siemens  af- 
firms? Let  us  suppose  that  the  air  of  the  room  is  raised 
from  30°  to  50°  by  convection  purely;  reference  to  tables 
based  on  the  researches  of  Kegnault,  shows  that  at  32°  the 
quantity  of  vapor  required  to  saturate  the  air  is  sufficient 
to  support  a  column  of  0'182  inch  of  mercury,  while  at  50° 
it  amounts  to  0'361,  or  nearly  double.  Thus  the  air,  in- 
stead of  being  in  a  condition  of  giving  away  its  moisture  to 
the  walls,  has  become  thirsty,  or  in  a  condition  to  take 
moisture  away  from  them  if  they  are  at  all  damp.  This  is 
the  case  whether  the  walls  remain  at  32°  or  are  raised  to 
any  higher  temperature  short  of  that  of  the  air. 

Thus  the  action  of  close  stoves  and  of  hot  surfaces  or 
pipes  of  any  kind  is  exactly  the  opposite  of  that  attributed 
to  them  by  Dr.  Siemens.  They  dry  the  air,  they  dry  the 
walls,  they  dry  the  ceiling,  they  dry  the  furniture  and  every- 
thing else  in  the  house. 

In  our  climate,  especially  in  the  infamous  jerry-built 
houses  of  suburban  London,  this  is  a  great  advantage.  Dr. 
Siemens  states  his  American  experience,  and  denounces 
such  heating  by  convection  because  the  close  stoves  there 
made  him  uncomfortable.  This  was  due  to  the  fact  that 
the  winter  atmosphere  of  the  United  States  is  very  dry,  even 
when  at  zero.  But  air,  when  raised  from  0°  to  60°,  acquires 
about  twelve  times  its  original  capacity  for  water.  The  air 
thus  simply  heated  is  desiccated,  and  it  desiccates  every- 
thing in  contact  with  it,  especially  the  human  body.  The 
lank  and  shriveled  aspect  of  the  typical  Yankee  is,  I  be- 
lieve, due  to  this.  He  is  a  desiccated  Englishman,  and  we 
should  all  grow  like  him  if  our  climate  were  as  dry  as  his.* 
The  great  fires  that  devastate  the  cities  of  the  United  States 
appear  to  me  to  be  due  to  this  general  desiccation  of  all 
building  materials,  rendering  them  readily  inflammable  and 
the  flames  difficult  of  extinction. 

When  an  undesiccated  Englishman,  or  a  German  endowed 


*  In  each  of  my  three  visits  to  America  I  lost  about  thirty  pounds 
in  weight,  which  I  recovered  within  a  few  months  of  my  return  to 
the  "home  country"  (of  English-speaking  nations).— RICHARD  A. 
PROCTOH. 


336  SCIENCE  IN  SHORT  CHAPTERS. 

with  a  wholesome  John  Bull  rotundity,  is  exposed  to  this 
superdried  air,  he  is  subjected  to  au  amount  of  bodily  evapo- 
ration that  must  be  perceptible  and  unpleasant.  The  dis- 
agreeable sensation  experienced  by  Dr.  Siemens  in  the  stoye- 
heated  railway  cars,  etc.,  were  probably  due  to  this. 

An  English  house,  enveloped  in  a  foggy  atmosphere,  and 
encased  in  damp  surroundings,  especially  requires  stove- 
heating,  and  the  most  inveterate  worshipers  of  our  national 
domestic  fetish,  the  open  grate,  invariably  prefer  a  stove  or 
hot-pipe-heated  room,  when  they  are  unconscious  of  the 
source  of  heat,  and  their  prejudice  hoodwinked.  I  have 
observed  this  continually,  and  have  often  been  amused  at 
the  inconsistency  thus  displayed.  For  example,  one  even- 
ing I  had  a  warm  contest  with  a  lady,  who  repeated  the 
usual  praises  of  a  cheerful  blaze,  etc.,  etc.  On  calling  after- 
wards, on  a  bitter  snowy  morning,  I  found  her  and  her 
daughters  sitting  at  work  in  the  billiard-room,  and  asked 
them  why.  "  Because  it  is  so  warm  and  comfortable."  This 
room  was  heated  by  an  eight-inch  steam-pipe,  running 
around  and  under  the  table,  to  prevent  the  undue  cooling 
of  the  indiarubber  cushions,  and  thus  the  room  was  warmed 
from  the  middle,  and  equally  and  moderately  throughout. 
The  large  reception-room,  with  blazing  fire,  was  scorching 
on  one  side,  and  freezing  on  the  other,  at  that  time  in  the 
morning. 

The  permeability  of  ill-constructed  iron  stoves  to  poison- 
ous carbonic  oxide,  which  riddles  through  red-hot  iron,  is 
a  real  evil,  but  easily  obviated  by  proper  lining,  The  friz  • 
zling  of  particles  of  organic  matter,  of  which  we  hear  so 
much,  is — if  it  really  does  occur — -highly  advantageous, 
seeing  that  it  must  destroy  organic  poison-germs. 

Under  some  conditions,  the  warm  air  of  a  room  does  de- 
posit moisture  on  its  cooler  walls.  This  happens  in  churches, 
concert-rooms,  etc.,  when  they  are  but  occasionally  used  in 
winter  time,  and  mainly  warmed  by  animal  heat,  by  con- 
gregational emanations  of  breath-vapor,  and  perspiration — 
i.e.,  with  warm  air  supersaturated  with  vapor.  Also,  when 
we  have  a  sudden  change  from  dry,  frosty  weather  to  warm 
and  humid.  Then  our  walls  may  be  streaming  with  con- 
densed water.  Such  cases  were  probably  in  the  mind  of  Dr. 


VENTILATION  BY  OPEN  FIREPLACES.         337 

Siemens  when  he  spoke;  but  they  are  quite  different  from 
stove-heating  or  pipe-heating,  which  increase  the  vapor 
capacity  of  the  heated  air,  without  supplying  the  demand 
it  creates. 


VENTILATION  BY  OPEN  FIREPLACES. 

THE  most  stubborn  of  all  errors  are  those  which  have 
been  acquired  by  a  sort  of  inheritance,  which  have  passed 
dogmatically  from  father  to  son,  or,  still  worse,  from 
mother  to  daughter.  They  may  become  superstitions  with- 
out any  theological  character.  The  idea  that  the  weather 
changes  with  the  moon,  that  wind  ''keeps  off  the.  rain," 
are  physical  superstitions  in  all  cases  where  they  are  blindly 
accepted  and  promulgated  without  any  examination  of  evi- 
dence. 

The  idea  that  our  open  fireplaces  are  necessary  for  ven- 
tilation is  one  of  these  physical  superstitions,  which  is  pro- 
ducing an  incalculable  amount  of  physical  mischief  through- 
out Britain.  A  little  rational  reflection  on  the  natural  and 
necessary  movements  of  our  household  atmospheres  dem- 
onstrates at  once  that  this  dogma  is  not  only  baseless,  but 
actually  expresses  the  opposite  of  the  truth.  I  think  I 
shall  be  'able  to  show  in  what  follows,  1st,  that  they  do  no 
useful  ventilation;  and,  2d,  that  they  render  systematic 
and  really  effective  ventilation  practically  impossible. 

Everybody  knows  that  when  air  is  heated  it  expands 
largely,  becomes  lighter,  bulk  for  bulk,  than  other  air  of 
lower  temperature;  and  therefore,  if  two  portions  of  air  of 
unequal  temperatures,  and  free  to  move,  are  in  contact 
with  each  other,  the  colder  will  flow  under  the  warmer, 
and  push  it  upwards.  The  latter  postulate  must  be  kept 
distinctly  in  view,  for  the  rising  of  warm  air  is  too  com- 
monly regarded  as  due  to  some  direct  uprising  activity  or 
skyward  affinity  of  its  own,  instead  of  being  understood  as 
an  indirect  result  of  gravitation.  It  is  the  downfalling  of 
the  cooler  air  that  causes  the  uprising  of  the  warmer. 

Now,  let  us  see  what,  in  accordance  with  the  above- 


338  SCIENCE  IN  SHORT  CHAPTERS. 

stated  simple  laws,  must  happen  in  an  ordinary  English 
apartment  that  is  fitted,  as  usual,  with  one  or  more  win- 
dows more  or  less  leak}7,  and  one  or  more  doors  in  like 
condition,  and  a  hole  in  the  wall  in  which  coal  is  burning 
in  an  iron  cage  immediately  beneath  a  shaft  that  rises  to 
the  top  of  the  house,  the  fire-hole  itself  having  an  extreme 
height  of  only  24  to  30  inches  above  the  floor,  all  the 
chimney  above  this  height  being  entirely  closed.  (I  find 
by  measurement  that  24  inches  is  the  usual  height  of  the 
upper  edge  of  the  chimney  opening  of  an  ordinary  "  reg- 
ister" stove.  Old  farm-house  fireplaces  are  open  to  the 
mantlepiece.) 

Now,  what  happens  when  a  heap  of  coal  is  burning  in 
this  hole?  Some  of  the  heat — from  10  to  20  per  cent,  ac- 
cording to  the  construction  of  the  grate — is  radiated  into 
the  room,  the  rest  is  conveyed  by  an  ascending  current  of 
air  up  the  chimney.  As  this  ascending  current  is  rendered 
visible  by  the  smoke  entangled  with  it,  no  further  demon- 
stration of  its  existence  is  needed. 

But  how  is  it  pushed  up  the  chimney?  Evidently  by 
cooler  air,  that  flows  into  the  room  from  somewhere,  and 
which  cooler  air  must  get  under  it  in  order  to  lift  it.  In 
ordinary  rooms  this  supply  of  air  is  entirely  dependent 
upon  their  defective  construction — bad  joinery;  it  enters 
only  by  the  crevices  surrounding  the  ill-fitting  ^windows 
and  doors,  no  specially  designed  opening  being  made  for  it. 
Usually  the  chief  inlet  is  the  space  under  the  door,  through 
which  pours  a  rivulet  of  cold  air,  that  spreads  out  as  a  lake 
upon  the  floor.  This  may  easily  be  proved  by  holding  a 
lighted  taper  in  front  of  the  bottom  door-chink  when  the 
window  and  other  door — if  any — are  closed,  and  the  fire  is 
burning  briskly.  At  the  same  time  more  or  less  of  cold 
air  is  poured  in  at  the  top  and  the  side  spaces  of  the  door 
and  through  the  window-chinks.  The  proportion  of  air 
entering  by  these  depends  upon  the  capacity  of  the  bottom 
door-chink.  If  this  is  large  enough  it  will  do  nearly  all 
the  work,  otherwise  every  other  possible  leakage,  including 
the  key-hole,  contributes. 

But  what  is  the  path  of  the  air  which  enters  by  these 
higher  level  openings?  The  answer  to  this  is  supplied  at 


VENTILATION  BY  OPEN  FIREPLACES.         339 

once  by  the  fact  that  such  air  being  colder  than  that  of  the 
room,  it  must  fall  immediately  it  enters.  The  rivulet 
under  the  door  is  thus  supplemented  by  cascades  pouring 
down  from  the  top  and  sides  of  the  door  and  the  top  and 
sides  of  the  windows,  all  being  tributaries  to  the  lake  of 
cold  air  covering  the  floor. 

The  next  question  to  be  considered  is,  what  is  the  depth 
of  this  lake?  In  this,  as  in  every  other  such  accumulation 
of  either  air  or  water,  the  level  of  the  upper  surface  of  the 
lake  is  determined  by  that  of  its  outlet.  The  outlet  in 
this  case  is  the  chimney  hole,  through  which  all  the  over- 
flow pours  upwards;  and,  therefore,  the  surface  of  the 
flowing  stratum  of  cold  air  corresponds  with  the  upper  part 
of  the  chimney  hole,  or  of  the  register,  where  register  stoves 
are  used. 

Below  this  level  there  is  abundant  ventilation,  above  it 
there  is  none.  The  cat  that  sits  on  the  hearth-rug  has  an 
abundant  supply  of  fresh  air,  and  if  we  had  trachea!  breath- 
ing apertures  all  down  the  sides  of  our  bodies,  as  caterpil- 
lars have,  those  on  our  lower  extremities  might  enjoy  the 
ventilation.  If  we  squatted  on  the  ground  like  savages 
something  might  be  said  for  the  fire-hole  ventilator.  But 
as  we  are  addicted  to  sitting  on  chairs  that  raise  our  breath- 
ing apparatus  considerably  above  the  level  of  the  top  of  the 
register,  the  maximum  efficiency  of  the  flow  of  cold  air  in 
the  lake  below  is  expressed  by  the  prevalence  of  chilblains 
and  rheumatism.* 

The  atmosphere  in  which  our  heads  are  immersed  is 
practically  stagnant;  the  radiations  from  the  fire,  plus  the 
animal  heat  from  our  bodies,  just  warm  it  sufficiently  to 
enable  the  cool  entering  air  to  push  it  upwards  above  the 
chimney  outlet  and  the  surface  of  the  lower  moving  stra- 
tum, and  to  keep  it  there  in  a  condition  of  stagnation. 

If  anybody  doubts  the  correctness  of  this  description,  ho 
has  only  to  sit  in  an  ordinary  English  room  where  a  good 
fire  is  burning — the  doors  and  windows  closed,  as  usual — 

*  Since  the  above  was  written,  a  correspondent  in  Paris  tells  me 
that  a  caricature  exists,  representing  a  Frenchman  enjoying  an  open 
fire  by  standing  on  his  head  in  the  middle  of  the  room. 


340  SCIENCE  IN  SHORT  CHAPTERS. 

and  then  to  blow  a  cloud  by  means  of  pipe,  cigar,  or  by 
burning  brown  paper  or  otherwise,  when  the  movements 
below  and  the  stagnation  above,  which  I  have  described, 
will  be  rendered  visible.  If  there  is  nobody  moving  about 
to  stir  the  air,  and  the  experiment  is  fairly  made,  the  level 
of  the  cool  lake  below  will  be  distinctly  shown  by  the 
clearing  away  of  the  smoke  up  to  the  level  of  the  top  of 
the  register  opening,  towards  which  it  may  be  seen  to 
sweep. 

Above  this  the  smoke-wreaths  will  remain  merely  wav- 
ing about,  with  slight  movements  due  to  the  small  inequali- 
ties of  temperature  caused  by  the  fraction  of  heat  radiated 
into  the  room  from  the  front  of  the  fire.  These  movements 
are  chiefly  developed  near  the  door  and  windows,  where 
the  above-mentioned  cascades  are  falling,  and  against  the 
walls  and  furniture,  where  feeble  convection  currents  are 
rising,  due  to  the  radiant  heat  absorbed  by  their  surfaces. 
The  stagnation  is  the  most  complete  about  the  middle  of 
the  room,  where  there  is  the  greatest  bulk  of  vacant  air- 
space. 

When  the  inlet  under  the  door  is  of  considerable  dimen- 
sions, there  may  be  some  escape  of  warmer  upper  air  at  the 
top  of  the  windows,  if  their  fitting  is  correspondingly  de- 
fective. These,  however,  are  mere  accidents;  they  are  not 
a  part  of  the  vaunted  chimney-hole  ventilation,  but  inter- 
ferences with  it. 

There  is  another  experiment  that  illustrates  the  absence 
of  ventilation  in  such  rooms  where  gas  is  burning.  It  is 
that  of  suspending  a  canary  in  a  cage  near  the  roof.  But 
this  is  cruel;  it  kills  the  bird.  It  would  be  a  more  satis- 
factory experiment  to  substitute  for  the  canary-bird  any 
wingless  biped  who,  after  reading  the  above,  still  maintains 
that  our  fire-holes  are  effective  ventilators. 

Not  only  are  the  fire-holes  worthless  and  mischievous 
ventilators  themselves,  but  they  render  efficient  ventilation 
by  any  other  means  practically  impossible.  The  "Arnott's 
ventilator"  that  we  sometimes  see  applied  to  the  upper  part 
of  chimneys  is  marred  in  its  action  "by  the  greedy  "  draught " 
below. 

The  tall  chimney-shaft,  with  a  fire  burning  immediately 


DOMESTIC  VENTILATION.  341 

below  it,  dominates  all  the  atmospheric  movement  in  the 
house,  unless  another  and  more  powerful  upcast  shaft  be 
somewhere  else  in  communication  with  the  apartments. 
But  in  this  case  the  original  or  ordinary  chimney  would  be 
converted  into  a  dowcast  shaft  pouring  air  downwards  into 
the  room,  instead  of  carrying  it  away  upwards.  I  need  not 
describe  the  sort  of  ventilation  thus  obtainable  while  the 
fire  is  burning  and  smoking. 

Effective  sanitary  ventilation  should  supply  gentle  and 
uniformly-diffused  currents  of  air  of  moderate  and  equal 
temperature  throughout  the  house.  We  talk  a  great  deal 
about  the  climate  here  and  the  climate  there;  and  when 
we  grow  old,  and  can  afford  it,  we  move  to  Bournemouth, 
Torquay,  Mentone,  Nice,  Algiers,  etc.,  for  better  climates, 
forgetting  all  the  while  that  the  climate  in  which  we  prac- 
tically live  is  not  that  out-of-doors,  but  the  indoor  climate 
of  our  dwellings,  the  which,  in  a  properly  constructed  house, 
may  be  regulated  to  correspond  to  that  of  any  latitude  we 
may  choose.  I  maintain  that  the  very  first  step  towards 
the  best  attainable  approximation  to  this  in  our  existing 
houses  is  to  brick  up,  cement  up,  or  otherwise  completely 
stop  up,  all  our  existing  fire-holes,  and  abolish  all  our  exist- 
ing fires. 

But  what  next?  The  reply  to  this  will  be  found  in  the 
next  chapter. 


DOMESTIC  VENTILATION. 

A  LESSON"  FROM  THE  COAL-PlTS. 

WE  require  in  our  houses  an  artificial  temperate  climate 
which  shall  be  uniform  throughout,  and  at  the  same  time 
we  need  a  gentle  movement  of  air  that  shall  supply  the 
requirements  of  respiration  without  any  gusts,  or  draughts, 
or  alternations  of  temperature.  Everybody  will  admit  that 
these  are  fundamental  desiderata,  but  whoever  does  so  be- 
comes thereby  a  denouncer  of  open-grate  fireplaces,  and  of 
every  system  of  heating  which  is  dependent  on  any  kind  of 


342  SCIENCE  IN  S30RT  CHAPTERS. 

stoves  with  fuel  burning  in  the  rooms  that  are  to  be  in- 
habited. All  such  devices  concentrate  the  heat  in  one  part 
of  each  room,  and  demand  the  admission  of  cold  air  from 
some  other  part  or  parts,  thereby  violating  the  primary  con- 
dition of  uniform  temperature.  The  usual  proceeding 
effects  a  specially  outrageous  violation  of  this,  as  I  showed 
in  the  last  chapter. 

I  might  have  added  domestic  cleanliness  among  the 
desiderata;  but  in  the  matter  of  fireplaces,  the  true-born 
Briton,  in  spite  of  his  fastidiousness  in  respect  to  shirt- 
collars,  etc.,  is  a  devoted  worshiper  of  dirt.  No  matter 
how  elegant  his  drawing-room,  he  must  defile  it  with  a  coal- 
scuttle, with  dirty  coals,  poker,  shovel,  and  tongs,  dirty  ash- 
pit, dirty  cinders,  ashes,  and  dust,  and  he  must  amuse  him- 
self by  doing  the  dirty  work  of  a  stoker  towards  his  "cheer- 
ful, companionable,  pokeable"  open  fire. 

It  is  evident  that,  in  order  to  completely  fulfil  the  first- 
named  requirements,  we  must,  in  winter,  supply  our  model 
residence  with  fresh  artificially-warmed  air,  and  in  summer 
with  fresh  cool  air.  How  is  this  to  be  done?  An  approach 
to  a  practical  solution  is  afforded  by  examining  what  is 
actually  done  under  circumstances  where  the  ventilation 
problem  presents  the  greatest  possible  difficulties,  and 
where,  nevertheless,  these  difficulties  have  been  effectually 
overcome.  Such  a  case  is  presented  by  a  deep  coal  mine. 
Here  we  have  a  little  working  world,  inhabited  by  men  and 
horses,  deep  in  the  bowels  of  the  earth,  far  away  from  the 
air  that  must  be  supplied  in  sufficient  quantities,  not  only  to 
overcome  the  vitiation  due  to  their  own  breathing,  but  also 
to  sweep  out  the  deadly  gaseous  emanations  from  the  coal 
itself. 

Imagine  your  dwelling-house  buried  a  quarter  of  a  mile 
of  perpendicular  depth  below  the  surface  of  the  earth,  and 
its  walls  giving  off  suffocating  and  explosive  gases  in  such 
quantities  that  steady  and  abundant  ventilation  shall  be  a 
matter  of  life  or  death,  and  that  in  spite  of  this  it  is  made 
so  far  habitable  that  men  who  spend  half  their  days  there 
retain  robust  health  and  live  to  green  old  age,  and  that 
horses  after  remaining  there  day  and  night  for  many  months 
actually  improve  in  condition.  Imagine,  further,  that  the 


DOMESTIC   VENTILATION.  343 

house  thus  ventilated  has  some  hundreds  of  small,  very  low- 
roofed  rooms,  and  a  system  of  passages  or  corridors  with  an 
united  length  of  many  miles,  and  that  its  inhabitants  count 
by  hundreds. 

Such  dwellings  being  thus  ventilated  and  rendered  habit- 
able for  man  and  beast,  it  is  idle  to  dispute  the  practical 
possibility  of  supplying  fresh  air  of  any  given  temperature 
to  a  mere  box  of  brick  or  stone,  standing  in  the  midst  of 
the  atmosphere,  and  containing  but  a  few  passages  and 
apartments. 

The  problem  is  solved  in  the  coal-pit  by  simply  and  skil- 
fully controlling  and  directing  the  natural  movements  of 
unequally-heated  volumes  of  air.  Complex  mechanical 
devices  for  forcing  the  ventilation  by  means  of  gigantic  fan- 
wheels,  etc.,  or  by  steam- jets,  have  been  tried,  and  are  now 
generally  abandoned.  An  inlet  and  an  outlet  are  provided, 
and  no  air  is  allowed  to  pass  inwards  or  outwards  by  any 
other  course  than  that  which  has  been  pre-arranged  for  the 
purposes  of  efficient  ventilation.  I  place  especial  emphasis 
on  this  condition,  believing  that  its  systematic  violation  is 
the  primary  cause  of  the  bungling  muddle  of  our  domestic 
ventilation. 

Let  us  suppose  that  we  are  going  to  open  a  coal-pit  to 
mine  the  coal  on  a  certain  estate.  We  first  ascertain  the 
"dip"  of  the  seam,  or  its  deviation  from  horizontality,  and 
then  start  at  the  lowest  part,  not,  as  some  suppose,  at  that 
part  nearest  to  the  surface.  The  reason  for  this  is  obvious 
on  a  little  reflection,  for  if  we  began  at  the  shallowest  part 
of  an  ordinary  water-bearing  stratum  we  should  have  to 
drive  down  under  water;  but,  by  beginning  at  the  lowest 
part  and  driving  upwards,  we  can  at  once  form  a  ' '  sumpf," 
or  bottom  receptacle,  to  receive  the  drainage,  and  from 
which  the  accumulated  water  may  be  pumped.  This,  how- 
ever, is  only  by  the  way,  and  not  directly  connected  with 
our  main  subject,  the  ventilation. 

In  order  to  secure  this,  the  modern  practice  is  to  sink 
two  pits,  "a  pair,"  as  they  are  called,  side  by  side,  at  any 
convenient  distance  from  each  other.  If  they  are  deep,  it 
becomes  necessary  to  '.eminence  ventilation  of  the  mere 
shafts  themselves  ;n  the  Bourse  of  sinking.  This  is  done 


344  SCIENCE  IN  SHOUT  CHAPTERS. 

by  driving  an  air-way — a  horizontal  tunnel  from  one  to  the 
other,  and  then  establishing  an  "  upcast"  in  one  of  them  by 
simply  lighting  a  fire  there.  This  destroys  the  balance  be- 
tween the  two  communicating  columns  of  air;  the  cooler 
column  in  the  shaft  without  a  fire,  being  heavier,  falls 
against  the  lighter  column,  and  pushes  it  up  just  as  the  air 
is  pushed  up  one  leg  of  an  \J  tube  when  we  pour  water 
down  the  other.  Even  in  this  preliminary  work,  if  the  pits 
are  so  deep  that  more  than  one  air-way  is  driven,  it  is 
necessary  to  stop  the  upper  ways  and  leave  only  the  lowest 
open,  in  order  that  the  ventilation  shall  not  take  a  short  and 
useless  cut,  as  it  does  up  our  fireplace  openings. 

Let  us  now  suppose  that  the  pair  of  pits  are  sunk  down 
to  the  seam,  with  a  further  extension  below  to  form  the 
water  sumpf.  There  are  two  chief  modes  of  working  a 
coal-seam:  the  " pillar  and  stall "  and  the  "long  wall,"  or 
more  modern  system.  For  present  illustration,  I  select  the 
latter  as  the  simplest  in  respect  to  ventilation.  This  method, 
as  ordinarily  worked,  consists  essentially  in  first  driving 
roads  through  the  coal,  from  the  pits  to  the  outer  boundary 
of  the  area  to  be  worked,  then  cutting  a  cross  road  that  shall 
connect  these,  thereby  exposing  a  "long  wall"  of  coal, 
which,  in  working,  is  gradually  cut  away  towards  the  pits, 
the  roof  remaining  behind  being  allowed  to  fall  in. 

Let  us  begin  to  do  this  by  driving,  first  of  all,  two  main 
roads,  one  from  each  pit.  It  is  evident  that  as  we  proceed 
in  such  burrowing,  we  shall  presently  find  ourselves  in  a 
cul  de  sac  so  far  away  from  the  outer  air  that  suffocation  is 
threatened.  This  will  be  equally  the  case  with  both  roads. 
Let  us  now  drive  a  cross-cut  from  the  end  of  each  main 
road,  and  thus  establish  a  communication  from  the  down- 
cast shaft  through  its  road,  then  through  the  drift  to  the 
upcast  road  and  pit.  But  in  order  that  the  air  shall  take 
this  roundabout  course,  we  must  close  the  direct  drift  that 
we  previously  made  between  the  two  shafts,  or  it  will  pro- 
ceed by  that  shorter  and  easier  course.  Now  we  shall  have 
air  throughout  both  our  main  roads,  and  we  may  drive  on 
further,  until  we  are  again  stopped  by  approximate  suffoca- 
tion. When  this  occurs,  we  make  another  cross-cut,  but 
in  order  that  it  may  act  we  must  stop  the  first  one.  So 


DOMESTIC  VENTILATION.  345 

we  go  on  until  we  reach  the  working,  and  then  the  long 
wall  itself  becomes  the  cross  communication,  and  through 
this  working-gallery  the  air  sweeps  freely  and  effectually. 

In  the  above  I  have  only  considered  the  simplest  possible 
elements  of  the  problem.  The  practical  coal-pit  in  full 
working  has  a  multitude  of  intervening  passages  and 
"splits,"  where  the  main  current  from  the  downcast  is 
divided,  in  order  to  proceed  through  the  various  streets  and 
lanes  of  the  subterranean  town  as  may  be  required,  and 
these  divided  currents  are  finally  reunited  ere  they  reach 
the  upcast  shaft  which  casts  them  all  out  into  the  upper 
air. 

In  a  colliery  worked  on  the  pillar  and  stall  system — i.e., 
by  taking  out  the  coal  so  as  to  leave  a  series  of  square 
chambers  with  pillars  of  coal  in  the  middle  to  support  the 
roof — the  windings  of  the  air  between  the  multitude  of 
passages  is  curiously  complex,  and  its  absolute  obedience  to 
the  commands  of  the  mining  engineer  proves  how  com- 
pletely the  most  difficult  problems  of  ventilation  may  be 
solved  when  ignorance  and  prejudice  are  not  permitted  to 
bar  the  progress  of  the  practical  applications  of  simple 
scientific  principles. 

Here  the  necessity  of  closing  all  false  outlets  is  strikingly 
demonstrated  by  the  mechanism  and  working  of  the  "stop- 
pings" or  partitions  that  close  all  unrequired  openings. 
The  air  in  many  pits  has  to  travel  several  miles  in  order  to 
get  from  the  downcast  to  the  upcast  shaft,  though  they 
may  be  but  a  dozen  yards  apart.  (Formerly  the  same  shaft 
served  both  for  up  and  down  cast,  by  making  a  wooden 
division  (a  brattice)  down  the  middle.  This  is  now  pro- 
hibited, on  account  of  serious  accidents  that  have  been 
caused  by  the  fracture  of  the  brattice.) 

But  it  would  not  do  to  carry  the  coal  from  the  workings 
to  the  pit  by  these  sinuous  air-courses.  What,  then,  is 
done  ?  A  direct  road  is  made  for  the  coal,  but  if  it  were 
left  open,  the  air  would  choose  it:  this  is  prevented  by  an 
arrangement  similar  to  that  of  canal  locks.  Valve-doors  or 
"  stoppings"  are  arranged  in  pairs,  and  when  the  "hurrier" 
arrives  with  his  corve,  or  pit  carriage,  one  door  is  opened, 
the  other  remaining  shut;  then  the  corve  is  hurried  into 


346  SCIENCE  IX  SHORT  CHAPTERS. 

the  space  between  the  doors,  and  the  entry-door  is  closed ; 
now  the  exit-door  is  opened,  and  thus  no  continuous  open- 
ing is  ever  permitted. 

Only  one  such  opening  would  derange  the  ventilation  of 
the  whole  pit,  or  of  that  portion  fed  by  the  split  thus  al- 
lowed to  escape.  It  would,  in  fact,  correspond  to  the 
action  of  our  open  fireplaces  in  rendering  effective  ventila- 
tion impossible. 

The  following,  from  the  report  of  the  Lords'  Committee 
on  Accidents  in  Coal  Mines,  1849,  illustrates  the  magnitude 
of  the  ventilation  arrangements  then  at  work.  In  the 
Hetton  Colliery  there  were  two  downcast  shafts  and  one 
upcast,  the  former  about  12  feet  and  the  latter  li  feet 
diameter.  There  were  three  furnaces  at  the  bottom  of  the 
upcast,  eacb^about  9  feet  wide  with  about  4  feet  length  of 
grate-bars;  the  depth  of  the  upcast  and  one  downcast  900 
feet,  and  of  the  other  downcast  1056  feet.  The  quantity 
of  air  introduced  by  the  action  of  these  furnaces  was 
168,560  cubic  feet  per  minute,  at  a  cost  of  about  eight  tons 
of  coal  per  day.  The  rate  of  motion  of  the  air  was  1097 
feet  per  minute  (above  12  miles  per  hour).  This  whole 
current  was  divided  by  splitting  into  16  currents  of  about 
11,000  cubic  feet  each  per  minute,  having,  on  an  average, 
a  course  of  4£  miles  each.  This  distance  was,  however, 
very  irregular —  the  greatest  length  of  course  being  9^ 
miles;  total  length  70  miles.  Thus  168,560  cubic  feet  of 
air  were  driven  through  these  great  distances  at  the  rate  of 
12  miles  per  hour,  and  at  a  cost  of  8  tons  of  coal  per  day. 

All  these  magnitudes  are  greatly  increased  in  coal-mines 
of  the  present  time.  As  much  as  250,000  cubic  feet  of 
air  per  minute  are  now  passed  through  the  shafts  of  one 
mine. 

The  problem  of  domestic  ventilation  as  compared  with 
coal-pit  ventilation  involves  an  additional  requirement, 
that  of  warming,  but  this  does  not  at  all  increase  the  diffi- 
culty, and  I  even  go  so  far  as  to  believe  that  cooling  in 
summer  may  be  added  to  warming  in  winter  by  one  and 
the  same  ventilating  arrangement.  As  I  am  not  a  builder, 
and  claim  no  patent  rights,  the  following  must  be  regarded 
as  a  general  indication,  not  as  a  working  specification,  of 


DOM/WIC    YKSTILATION.  347 

ray  scheme  for  domestic  ventilation  and  the  regulation  of 
home  climate. 

The  model  house  must  have  an  upcast  shaft,  placed  as 
nearly  in  the  middle  of  the  building  as  possible,  with  which 
every  room  must  communicate  either  by  a  direct  opening 
or  through  a  lateral  shaft.  An  ordinary  chimney  built  in 
the  usual  manner  is  all  that  is  required  to  form  such  a 
main  shaft. 

There  must  be  no  stoves  nor  any  fireplaces  in  any  room 
excepting  the  kitchen,  of  which  anon.  All  the  windows 
must  be  made  to  fit  closely,  as  nearly  air-tight  as  possible. 
No  downcast  shaft  is  required,  the  pressure  of  the  sur- 
rounding outer  atmosphere  being  sufficient.  Outside  of 
the  house,  or  on  the  ground  floor  (on  the  north  side,  if 
possible),  should  be  a  chamber  heated  by  flues,  hot  air, 
steam,  a  suitable  stove,  or  water-pipes,  and  with  one  ad- 
justable opening  communicating  with  the  outer  fresh  air, 
and  another  on  the  opposite  side  connected  by  a  shaft  or 
air- way  with  the  hall  of  the  ground  floor  and  the  general 
staircase. 

Each  room  to  have  an  opening  at  its  upper  part  com- 
municating with  the  chimney,  like  an  Arnott's  ventilator, 
and  capable  of  adjustment  as  regards  area  of  aperture, 
and  other  openings  of  corresponding  or  excessive  com- 
bined area  leading  from  the  hall  or  staircase  to  the  lower 
part  of  the  room.-  These  may  be  covered  with  perforated 
zinc  or  wire  gauze,  so  that  the  air  may  enter  in  a  gentle, 
broken  stream. 

All  the  outer  house-doors  must  be  double,  i.e.,  with  a 
porch  or  vestibule,  and  only  one  of  each  pair  of  doors 
opened  at  once.  These  should  be  well  fitted,  and  the  stair- 
case air-tight.  The  kitchen  to  communicate  with  the  rest 
of  the  house  by  similar  double  doors,  and  the  kitchen  fire 
to  communicate  directly  with  the  upcast  shaft  or  chimney 
by  as  small  a  stove-pipe  as  practicable.  The  kitchen  fire 
will  thus  start  the  upcast  and  commence  the  draught  of  air 
from  the  warm  chamber  through  the  house  towards  the 
several  openings  into  the  shaft.  In  cold  weather,  this  up- 
cast action  will  be  greatly  reinforced  and  maintained  by  the 
general  warmth  of  all  the  air  in  the  house,  which  itself  will 


348  SCIENCE  IN  SHORT  CHAPTERS. 

bodily  become  an  upcast  shaft  immediately  the  inner  tem- 
perature exceeds  that  of  the  air  outside. 

But  the  upcast  of  warm  air  can  only  take  place  by  the 
admission  of  fresh  air  through  the  heating  chamber,  thence 
to  hall  and  staircase,  and  thence  onward  through  the  rooms 
into  the  final  shaft  or  chimney. 

The  openings  into  and  out  of  the  rooms  being  adjustable, 
they  may  be  so  regulated  that  each  shall  receive  an  equal 
share  of  fresh  warm  air;  or,  if  desired,  the  bedroom  chim- 
ney valves  may  be  closed  in  the  daytime,  and  thus  the  heat 
economized  by  being  used  only  for  the  day  rooms;  or,  vice 
versa,  the  communication  between  the  upcast  shaft  and  the 
lower  rooms  may  be  closed  in  the  evening,  and  thus  all  the 
warm  air  be  turned  into  the  bedrooms  at  bedtime. 

If  the  area  of  the  entrance  apertures  of  the  rooms  exceeds 
that  of  the  outlet,  only  the  latter  need  be  adjusted;  the 
room  doors  may,  in  fact,  be  left  wide  open  without  any 
possibility  of  "draught,"  beyond  the  ventilation  current, 
which  is  limited  by  the  dimension  of  the  opening  from  the 
room  into  the  shaft  or  chimney. 

So  far,  for  winter  time,  when  the  ventilation  problem  is 
the  easiest,  because  then  the  excess  of  inner  warmth  con- 
verts the  whole  house  into  an  upcast  shaft,  and  the  whole 
outer  atmosphere  becomes  a  downcast.  In  the  summer 
time,  the  kitchen  fire  would  probably  be  insufficient  to 
secure  a  sufficiently  active  upcast. 

To  help  this  there  should  be  in  one  of  the  upper  rooms 
— say  an  attic — an  opening  into  the  chimney  secured  by  a 
small  well-fitting  door;  and  altogether  enclosed  within  the 
chimney  a  small  automatic  slow-combustion  stove  (of  which 
many  were  exhibited  in  South  Kensington,  that  require 
feeding  but  once  in  twenty-four  hours),  or  a  large  gas- 
burner.  The  heating-chamber  below  must  now  be  con- 
verted into  a  cooling  chamber  by  an  arrangement  of  wet 
cloths,  presently  to  be  described,  so  that  all  the  air  entering 
the  house  shall  be  reduced  in  temperature. 

Or  the  winter  course  of  ventilation  may  be  reversed  by 
building  a  special  shaft  connected  with  the  kitchen  fire, 
which,  in  this  case,  must  not  communicate  with  the  house 
shaft.  This  special  shaft  may  thus  be  made  an  upcast,  and 


DOMESTIC  VENTILATION.  349 

the  rooms  supplied  with  air  from  above  down  the  house 
shaft,  through  the  rooms,  and  out  of  the  kitchen  via  the 
winter  heating-chamber,  which  now  has  its  communication 
with  the  outside  air  closed. 

Reverting  to  the  first-named  method,  which  I  think  is 
better  than  the  second,  besides  being  less  expensive,  I  must 
say  a  few  concluding  words  on  an  important  supplementary 
advantage  which  is  obtainable  wherever  all  the  air  entering 
the  house  passes  through  one  opening,  completely  under 
control,  like  that  of  our  heating-chamber.  The  great  evil 
of  our  town  atmosphere  is  its  dirtiness.  In  the  winter  it  is 
polluted  with  soot  particles;  in  the  dry  summer  weather, 
the  traffic  and  the  wind  stir  up  and  mix  with  it  particles  of 
dust,  having  a  composition  that  is  better  ignored,  when  we 
consider  the  quantity  of  horse-dung  that  is  dried  and  pul- 
verized on  our  roadways.  All  the  dust  that  falls  on  our 
books  and  furniture  was  first  suspended  in  the  air  we  breathe 
inside  our  rooms.  Can  we  get  rid  of  any  practically  impor- 
tant portion  of  this? 

I  am  able  to  answer  this  question,  not  merely  on  theo- 
retical grounds,  but  as  a  result  of  practical  experiments 
described  in  the  following  chapter,  in  which  is  reprinted 
a  paper  I  read  at  the  Society  of  Arts,  March  19,  1879,  re- 
commending the  enclosure  of  London  back  yards  with  a 
roofing  of  "wall  canvas/' or  " paperhanger's  canvas,"  so 
as  to  form  cheap  conservatories.  This  canvas,  which  costs 
about  threepence  per  square  yard,  is  a  kind  of  coarse, 
strong,  fluffy  gauze,  admitting  light  and  air,  but  acting 
very  effectively  as  an  air  filter,  by  catching  and  stopping 
the  particles  of  soot  and  dust  that  are  so  fatal  to  urban 
vegetation. 

1  propose,  therefore,  that  this  well-tried  device  should  be 
applied  at  the  entrance  aperture  of  our  heating  chamber, 
that  the  screens  shall  be  well  wetted  in  the  summer,  in  order 
to  obtain  the  cooling  effect  of  evaporation,  and  in  the  winter 
shall  be  either  wet  or  dry,  as  may  be  found  desirable.  The 
Parliament  House  experiments  prove  that  they  are  good 
filters  when  wetted,  and  mine  that  they  act  similarly  when 
dry. 

By  thus  applying  the  principles  of  colliery  ventilation  to 


350  SCIENCE  IN  SHORT  CHAPTERS. 

a  specially-constructed  house,  we  may,  I  believe,  obtain  a 
perfectly  controllable  indoor  climate,  with  a  range  of  varia- 
tion not  exceeding  four  or  five  degrees  between  the  warmest 
and  the  coldest  part  of  the  house,  or  eight  or  nine  degrees 
between  summer  and  winter,  and  this  may  be  combinbd 
with  an  abundant  supply  of  fresh  air  everywhere,  all  filtered 
from  the  grosser  portions  of  its  irritant  dust,  which  is  posi- 
tively poisonous  to  delicate  lungs,  and  damaging  to  all. 
The  cost  of  fuel  would  be  far  less  than  with  existing  arrange- 
ments, and  the  labor  of  attending  to  the  one  or  two  fires 
and  the  valves  would  also  be  less  than  that  now  required 
in  the  carrying  of  coal-scuttles,  the  removal  of  ashes,  the 
cleaning  of  fireplaces,  and  the  curtains  and  furniture  they 
befoul  by  their  escaping  dust  and  smoke. 

It  is  obvious  that  such  a  system  of  ventilation  may  even 
be  applied  to  existing  houses  by  mending  the  ill-fitting 
windows,  shutting  up  the  existing  fire-holes,  and  using  the 
chimneys  as  upcast  shafts  in  the  manner  above  described. 
This  may  be  done  in  the  winter,  when  the  problem  is  easiest, 
and  the  demand  for  artificial  climate  the  most  urgent;  but 
I  question  the  possibility  of  summer  ventilation  and  tem- 
pering of  climate  in  anything  short  of  a  specially-built  house 
or  a  materially  altered  existing  dwelling.  There  are  doubt- 
less some  exceptions  to  this,  where  the  house  happens  to  be 
specially  suitable  and  easily  adapted,  but  in  ordinary  houses 
we  must  be  content  with  the  ordinary  devices  of  summer 
ventilation  by  doors  and  windows,  plus  the  upper  openings 
of  the  rooms  into  the  chimneys  expanded  to  their  full 
capacity,  and  thus  doing,  even  in  summer,  far  better  venti- 
lating work  than  the  existing  fire-holes  opening  in  the  wrong 
place. 

I  thus  expound  my  own  scheme,  not  because  I  believe  it 
to  be  perfect,  but,  on  the  contrary,  as  a  suggestive  project 
to  be  practically  amended  and  adapted  by  others  better 
able  than  myself  to  carry  out  the  details.  The  feature  that 
I  think  is  novel  and  important  is  that  of  consciously  and 
avowedly  applying  to  domestic  ventilation  the  principles 
that  have  been  so  successfully  carried  out  in  the  far  more 
difficult  problem  of  subterranean  ventilation. 

The  dishonesty  of  the  majority  of  the  modern  builders 


HOME  GARDENS  FOR  SMOKY  TOWNS.          351 

of  suburban  "villa  residences"  is  favorable  to  this  and  otber 
similar  radical  household  .reforms,  as  thousands  of  these 
wretched  tenements  must  sooner  or  later  be  pulled  down, 
or  will  all  come  down  together  without  any  pulling  the  next 
time  we  experience  one  of  those  earthquake  tremors  which 
visit  England  about  once  in  a  century. 


HOME  GARDENS  FOR  SMOKY  TOWNS. 

THE  poetical  philanthropists  of  the  shepherd  and  shep- 
herdess school,  if  any  still  remain,  may  find  abundant 
material  for  their  doleful  denunciations  of  modern  civiliza- 
tion on  journeying  among  the  house-tops  by  any  of  our 
over-ground  metropolitan  and  suburban  railways,  and  con- 
templating therefrom  the  panorama  presented  by  a  rapid 
succession  of  London  back  yards.  The  sandy  Sahara,  and 
the  saline  deserts  of  Central  Asia,  are  bright  and  breezy, 
rural  and  cheerful,  compared  with  these  foul,  soot-smeared, 
lumber- strew n  areas  of  desolation. 

The  object  of  this  paper  is  to  propose  a  remedy  for  these 
metropolitan  measle-spots,  by  converting  them  into  gardens 
that  shall  afford  both  pleasure  and  profit  to  all  concerned. 

A  very  obvious  mode  of  doing  this  would  be  to  cover 
them  with  glass,  and  thus  convert  them  into  winter  gardens 
or  conservatories.  The  cost  of  this  at  once  places  it  beyond 
practical  reach  ;  but  even  if  the  cost  were  disregarded,  as  it 
might  be  in  some  instances,  such  covering  in  would  not  be 
permissible  on  sanitary  grounds ;  for,  doleful  and  dreary 
as  they  are,  the  back  yards  of  London  perform  one  very 
important  and  necessary  function;  they  act  as  ventilation- 
shafts  between  the  house-backs  of  the  more  densely  popu- 
lated neighborhoods. 

At  one  time  I  thought  of  proposing  the  establishment  of 
horticultural  home  missions  for  promoting  the  dissemina- 
tion of  flower-pot  shrubs  in  the  metropolis,  and  of  showing 
how  much  the  atmosphere  of  London  would  be  improved 
if  every  London  family  had  one  little  sweetbriar  bush,  a 


352  SCIENCE  IN  SffORT  CHAPTERS. 

layender  plant,  or  a  hardy  heliotrope  to  each  of  its  mem- 
bers ;  so  that  a  couple  of  million  of  such  ozone  generators 
should  breathe  their  sweetness  into  the  dank  and  dead  at- 
mosphere of  the  denser  central  regions  of  London. 

A  little  practical  experience  of  the  difficulty  of  growing  a 
clean  cabbage,  or  maintaining  alive  any  sort  of  shrub  in 
the  midst  of  our  soot-drizzle,  satisfied  me  that  the  mission 
would  fail,  even  though  the  sweetbriars  were  given  aAvay  by 
the  district  visitors  ;  for  these  simple  hardy  plants  perish  in 
a  mid-London  atmosphere  unless  their  leaves  are  periodi- 
cally sponged  and  syringed,  to  wash  away  the  soot  particles 
that  otherwise  close  their  stomata  and  suffocate  the  plant. 

It  is  this  deposit  that  stunts  or  destroys  all  our  London 
vegetation,  with  the  exception  of  those  trees  which,  like  the 
planes  have  a  deciduous  bark  and  cuticle. 

Some  simple  and  inexpensive  means  of  protecting  vege- 
tation^from  London  soot  are,  therefore,  most  desirable. 

When  the  Midland  Institute  commenced  its  existence 
in  temporary  buildings  in  Cannon  Street,  Birmingham,  in 
1854,  I  was  compelled  to  ventilate  my  class-rooms  by  tem- 
porary devices,  one  of  which  was  to  throw  open  the  existing 
windows,  and  protect  the  students  from  the  heavy  blast  of 
entering  air  by  straining  it  through  a  strong  gauze-like  fabric 
stretched  over  the  opening. 

After  a  short  time  the  tammy  became  useless  for  its  in- 
tended purpose  ;  its  interstices  were  choked  with  a  deposit 
of  carbon.  On  examining  this,  I  found  that  the  black  de- 
posit was  all  on  the  outside,  showing  that  a  filtration  of 
the  air  had  occurred.  Even  when  the  tammy  was  replaced 
by  perforated  zinc,  puttied  into  the  window  frames  in  the 
place  of  glass  panes,  it  was  found  necessary  to  frequently 
wash  the  zinc,  in  order  to  keep  the  perforations  open. 

The  recollection  of  this  experience  suggested  that  if  a 
gauze-like  fabric,  cheaper  and  stronger  than  the  tammy,  can 
be  obtained,  and  a  sort  of  greenhouse  made  with  this  in  the 
place  of  glass,  the  problem  of  converting  London  back- 
yards into  gardens  might  be  solved. 

After  some  inquiries  and  failures  in  the  trial  of  various 
cheap  fabrics,  I  found  one  that  is  already  to  be  had,  and 
well  adapted  to  the  purpose.  It  is  called  "wall  canvas," 


HOME  GARDENS  FOB  SMOKY  TOWNS.          353 

or  "  scrim,"  is  retailed  at  ?>\d.  per  yard,  and  is  one  yard  wide. 
If  I  am  rightly  informed,  it  may  be  bought  in  wholesale 
quantities  at  about  2±d.  per  square  yard,  i.e.,  one  farthing 
per  square  foot.  This  fabric  is  made  of  coarse  unbleached 
thread  yarn,  very  strong  and  open  in  structure.  The  light 
passes  so  freely  through  it  that  when  hung  before  a  window 
the  loss  of  light  in  the  room  is  barely  perceptible.  When 
a  piece  is  stretched  upon  a  frame,  a  printed  placard,  or  even 
a  newspaper,  may  be  read  through  it. 

The  yarn  being  loosely  spun,  fine  fluffy  filaments  stand 
out  and  bar  the  interstices  against  the  passage  of  even  very 
minute  carbonaceous  particles.  These  filaments  may  be 
seen  by  holding  it  up  to  the  light. 

The  fabric  being  one  yard  wide,  and  of  any  length  re- 
quired, all  that  is  needed  for  a  roof  or  side  walls  is  a  skele- 
ton made  of  lines  or  runs  of  quartering,  at  3  feet  distance 
from  each  other.  The  cost  of  such  quartering,  made  of 
pitch  pine,  the  best  material  for  outside  work,  is  under 
one  penny  per  foot  run;  of  common  white  deal,  about 
three  farthings.  Thus  the  cost  of  material  for  a  roof,  sa^ 
a  lean-to  from  a  wall-top  to  the  side  of  a  house,  which  would 
be  the  most  commonly  demanded  form  of  30  feet  by  10  feet, 
i.e.,  300  square  ieet,  would  be— 

«.  d. 

110  feet  of  quartering  (11  lengths)  at,  Id 9    2 

300  square  feet  of  canvas,  at  li 6    3  * 

Nails  and  tacks,  say 1    0 

16    5 

The  size  of  the  quartering  proposed  is  2£  by  1£  inch, 
which,  laid  edgewise,  would  bear  the  weight  of  a  man  on 
a  plank  while  nailing  down  the  canvas.  The  canvas  has 
a  stout  cord-like  edge  or  selvage,  that  holds  the  nails  well. 

I  find  that  what  are  called  "French  tacks"  are  well 
suited  for  nailing  it  down.  They  are  made  of  wire,  well 
pointed,  have  good-sized  flat  clout  heads,  and  are  very 
cheap.  They  are  incomparably  superior  to  the  ordinary 
rubbish  sold  as  "  tin  tacks"  or  "cut  tacks."  The  construc- 


*  See  foot-note,  page  365. 


354  SCIENCE  IN  SHORT  CHAPTERS. 

tion  of  such  a  conservatory  is  so  simple  that  any  industrious 
artisan  or  clerk  with  any  mechanical  ingenuity  could,  with 
the  aid  of  a  boy,  do  it  all  himself.  No  special  skill  is  re- 
quired for  any  part  of  the  work,  and  no  other  tools  than  a 
rule,  a  saw,  and  a  hammer.  Side  posts  and  stronger  end 
rails  would  in  some  cases  be  demanded. 

I  have  not  been  able  to  fairly  carry  out  this  project,  inas- 
much as  I  reside  at  Twickenham,  beyond  the  reach  of  the 
black  showers  of  London  soot.  I  have,  however,  made 
some  investigations  relative  to  the  climate  which  results 
from  such  enclosure. 

This  was  done  by  covering  a  small  skeleton  frame  with 
the  canvas,  putting  it  upon  the  ground  over  some  cabbage 
plants,  etc.,  and  placing  registering  thermometers  on  the 
ground  inside,  and  in  similar  position  outside  the  frame  ; 
also  by  removing  the  glass  cover  of  a  cucumber  frame,  and 
replacing  it  by  a  frame  on  which  the  canvas  is  stretched. 

I  planted  300  cabbages  in  November  last,  in  rows  on  the 
open  ground,  and  placed  the  canvas-covered  frame  over  18 
of  them.  At  the  present  date,  March  15,  only  26  of  the 
282  outside  plants  are  visible  above  the  ground.  All  the 
rest  have  been  cut  off  by  the  severe  frost.  Under  the  frame 
all  are  flourishing. 

I  find  that  the  difference  between  the  maximum  and  the 
minimum  temperatures  varies  with  the  condition  of  the 
sky.  In  cloudy  weather,  the  difference  between  the  inside 
and  the  outside  rarely  exceeds  2°  Fahr.,  and  occasionally 
there  is  no  difference.  In  clear  weather  the  difference-  is 
considerable.  During  the  day  the  outside  thermometer  re- 
gisters from  four  or  five  to  seven  or  eight  degrees  above  that 
within  the  screen  during  the  sunshine.  At  night  the  mini- 
mum thermometers  show  a  difference  which  in  one  case 
reached  14°,  i.e.,  between  23d  and  24th  February,  when 
the  lowest  temperature  I  have  observed  was  reached.  The 
.outside  thermometer  then  fell  to  8°  Fahr..  the  inside  to 
22°.  On  the  night  of  the  24th  and  25th  they  registered 
15£°  outside,  25^°  inside.  On  other,  or  ordinary  clear  frosty 
nights,  with  E.  and  N.  and  N.E.  winds,  the  difference  has 
ranged  between  4°  and  6°,  usually  within  a  fraction  of  the 
average,  5°. 


HOME  GARDEXS  FOR  SMOKY  TOWNS.          355 

The  uniformity  of  this  during  the  recent  bright  frosty 
nights,  followed  by  warm  sunny  days,  has  been  very  re- 
markable, so  much  so  that  I  think  I  may  venture  to  state 
that  5°  may  be  expected  as  the  general  protecting  effect  of 
a  covering  of  such  canvas  from  the  mischievous  action  of 
our  spring  frosts  which  are  due  to  nocturnal  radiation  into 
free  space.  Thus  we  obtain  a  climate,  the  mean  of  which 
would  be  about  the  same  as  outside,  but  subject  to  far  less 
variation.  How  will  this  affect  the  growth  of  plants  desi- 
rable to  cultivate  in  the  proposed  canvas  conservatories? 

In  the  first  place,  we  must  not  expect  the  results  obtain- 
able under  glass,  which  by  freely  transmitting  the  bright 
solar  rays,  and  absorbing  or  resisting  the  passage  of  the  ob- 
scure rays  from  the  heated  soil,  produces,  during  sunshine, 
a  tropical  climate  here  in  our  latitudes.  We  may  therefore 
at  once  set  aside  any  expectation  of  rearing  exotic  plants 
of  any  kind;  even  our  native  and  acclimatized  plants,  which 
require  the  maximum  heat  of  English  sunshine,  are  not 
likely  to  flourish. 

On  the  other  hand,  all  those  which  demand  moderate 
protection  from  sudden  frosts,  especially  from  spring  frosts, 
and  which  flourish  when  we  have  a  long  mild  spring  and 
summer,  are  likely  to  be  reared  with  especial  success. 

This  includes  nearly  all  our  table  vegetables,  our  salads, 
kitchen  herbs,  and  British  fruits,  all  our  British  and  many 
exotic  ferns,  and,  I  believe,  most  of  our  out-of-door  plants, 
both  wild  and  cultivated. 

;t.  As  the  subject  of  ornamental  flowers  is  a  very  large  one, 
and  one  with  the  cultivation  of  which  I  have  very  little 
practical  acquaintance,  I  will  pass  it  over;  but  must  simply 
indicate  that,  in  respect  to  ferns,  the  canvas  enclosure 
offers  a  combination  of  most  desirable  conditions.  The 
slight  shade,  the  comparatively  uniform  temperature,  and 
the  moderated  exhalation,  are  just  those  of  a  luxuriant  fern 
dingle. 

Respecting  the  useful  or  economic  products  I  can  speak 
with  more  confidence,  that  being  my  special  department  in 
our  family  or  home  gardening,  which,  as  physical  discip- 
line, I  have  always  conducted  myself,  with  a  minimum  of 
professional  aid. 


356  SCIENCE  IN  SHORT  CHAPTERS, 

My  experience  of  a  small  garden  leads  me  to  give  first 
place  to  salads.  A  yard  square  of  rich  soil,  well  managed, 
will  yield  a  handsome  and  delicious  weekly  dish  of  salad 
nearly  all  the  year  round;  and,  at  the  same  rate,  seven  or 
eight  square  yards  will  supply  a  daily  dish — including  let- 
tuces, endives,  radishes,  spring  onions,  mustard,  and  vari- 
ous kinds  of  cress,  and  fancy  salads,  all  in  a  state  of  fresh- 
ness otherwise  unattainable  by  the  Londoner.  My  only 
difficulty  has  arisen  from  irregularity  of  supply.  From  the 
small  area  allowed  for  salads,  I  have  been  over-supplied  in 
July,  August,  and  September,  and  reduced  to  in-door  or 
frame-grown  mustard  and  cress  during  the  winter.  With 
the  equable  insular  climate  obtainable  under  the  canvas, 
this  difficulty  will  be  greatly  diminished;  and  besides  this, 
most  of  the  salads  are  improved  by  partial  shade,  lettuces 
and  endives  more  blanched  and  delicate  than  when  exposed 
to  scorching  sun,  radishes  less  fibrous,  mustard,  cress,  etc., 
milder  in  flavor  and  more  succulent. 

The  multitude  of  savory  kitchen  herbs  that  are  so  sadly 
neglected  in  English  cookery  (especially  in  the  food  of  the 
town  artisan  and  clerk),  all,  with  scarcely  an  exception, 
demand  an  equable  climate  and  protection  from  our  de- 
structive spring  frosts.  These  occupy  very  little  space, 
less  even  than  salads,  and  are  wanted  in  such  small  quanti- 
ties at  a  time,  and  so  frequently,  that  the  hard-worked 
housewife  commonly  neglects  them  altogether,  rather  than 
fetch  them  from  the  greengrocer's  in  their  exorbitantly 
small  pennyworths.  If  she  could  step  into  the  back  yard, 
and  gather  her  parsley,  sage,  thyme,  winter  savory,  mint, 
marjoram,  bay  leaf,  rosemary,  etc.,  the  dinner  would  be- 
come far  more  savory,  and  the  demand  for  the  alcoholic 
substitutes  for  relishing  food  proportionably  diminished. 

My  strongest  anticipations,  however,  lie  in  the  direction 
of  common  fruits — apples,  pears,  cherries,  plums  of  all 
kinds,  peaches,  nectarines,  gooseberries,  currants,  raspber- 
ries, strawberries,  etc. 

The  most  luxuriant  growth  of  cherries,  currants,  goose- 
berries, and  raspberries  I  have  ever  seen  in  any  part  of  the 
world  that  I  have  visited,  is  where  they  might  be  least  ex- 
pected, viz.,  Norway;  not  the  South  of  Norway  merely,  but 


HOME  GARDENS  FOR  SMOKY  TOWNS.          357 

more  particularly  in  the  valleys  that  slope  from  the  500 
square  miles  of  the  perpetual  ice  desert  of  the  Justedal 
down  to  the  Sognefjord,  latitude  61°  to  61|°,  considerably 
to  the  north  of  the  northernmost  of  the  Shetland  Islands. 
The  cherry  and  currant  trees  are  marvelous  there. 

In  the  garden  of  one  of  the  farm  stations  (Sande)  I 
counted  70  fine  bunches  of  red  currants  growing  on  six 
inches  of  one  of  the  overladen  down-hanging  stems  of  a 
currant  bush.  Cherries  are  served  for  dessert  by  simply 
breaking  off  a  small  branch  of  the  tree  and  bringing  it  to 
the  table — the  fruit  almost  as  many  as  the  leaves. 

This  luxuriance  I  attribute  to  two  causes.  First,  that  in 
that  part  of  Norway  the  winter  breaks  up  suddenly  at  about 
the  beginning  of  June,  and  not  until  then,  when  night 
frosts  are  no  longer  possible,  do  the  blossoms  appear.  It 
was  on  the  24th  August  that  I  counted  the  70  bunches  of 
ripe  currants.  The  second  cause  is  the  absence  of  sparrows 
and  other  destructive  small  birds  that  devour  our  currants 
for  the  seeds'  sake  before  they  ripen,  and  our  cherries  im- 
mediately on  ripening.  These  ara  preceded  by  the  bull- 
finches that  feed  on  the  tender  hearts  of  the  buds. of  most 
of  our  fruit  trees.  Those  who  believe  the  newspaper  myths 
which  represent  such  thick-billed  birds  eating  caterpillars, 
should  make  observations  and  experiments  for  themselves 
as  I  have  done. 

In  our  canvas  conservatories  neither  sparrows  nor  cater- 
pillars, nor  wasps,  or  other  fruit-stealers  will  penetrate, 
nor  will  the  spring  frosts  nip  the  blossoms  that  open  out 
in  April.  All  the  conditions  for  full  bearing  are  there  ful- 
filled, and  the  ripening  season,  though  not  so  intense,  will 
be  prolonged.  We  shall  have  an  insular  Jersey  climate  in 
London,  where  the  mean  temperature  is  higher  than  in  the 
country  around,  and,  if  I  am  not  quite  deluded,  we  shall 
be  able  to  grow  the  choicest  Jersey  pears,  those  that  best 
ripen  by  hanging  on  the  tree  until  the  end  of  December, 
and  fine  peaches,  which  are  commonly  destroyed  by  putting 
forth  their  blossoms  so  early.  All  the  hundred  and  one 
varieties  of  plums  and  damsons,  greengages,  etc.,  that 
can  grow  in  temperate  climates  will  be  similarly  pro- 
tected from  the  frosts  that  kill  their  early  blossoms,  and 


358  SCIENCE  IN  SHORT  CHAPTERS. 

the  birds  and  the  wasps  that  will  not  give  them  time  to 
ripen  slowly. 

I  have  little  doubt  that  if  my  project  is  carried  out,  any 
London  householder,  whether  rich  or  poor,  may  indulge 
in  delicious  desserts  of  rich  fruit  all  grown  on  the  sites  of 
their  own  now  dirty  and  desolate  back-yards;  that  if  prizes 
be  given  for  the  most  prolific  branches  of  cherry  and  plum 
trees,  gooseberry  and  currant  bushes,  the  gardens  of  the 
Seven-dials  and  of  classic  St.  Giles's  may  carry  off  some  of 
the  gold  medals;  and  that,  by  judicious  economy  of  space 
and  proper  pruning  of  the  trees,  the  canvas  conservatories 
may  be  made  not  only  to  serve  as  orchard  houses,  but  also 
to  grow  the  salads,  kitchen  herbs,  and  green  vegetables  for 
cookery,  under  the  fruit  trees  or  close  around  their  stems. 

Among  the  suitable  vegetables,  I  may  name  a  sort  of 
perennial  spinach  which  yields  a  wonderful  amount  of  pro- 
duce on  a  small  area.  Four  years  ago  I  took  the  house  in 
which  I  now  reside,  and  found  the  garden  overgrown  with 
a  weed  that  appeared  like  beet,  the  leaves  being  much  lar- 
ger than  ordinary  spinach.  I  tried  in  vain  to  eradicate  it, 
then  gave  some  leaves  to  my  fowls.  They  ate  them  greed- 
ily. After  this  I  had  some  boiled,  and  found  that  the 
supposed  weed  is  an  excellent  spinach,  which  may  be  sown 
broadcast  in  thick  patches,  without  any  interspaces,  and 
cut  down  again  and  again  all  the  year  round,  fresh  leaves 
springing  up  from  the  roots  until  the  autumn,  when  it 
throws  up  tall  flowering  stems,  and  yields  an  abundant 
crop  of  seeds.  I  have  some  now,  self-sown,  that  have 
survived  the  whole  of  the  late  severe  winter,  while  turnip- 
tops,  cabbages,  and  everything  else  have  perished.  I  have 
sown  the  ordinary  spinach  seed  in  the  usual  manner  in 
rows,  and  comparing  it  with  the  self-sown  dense  patches 
of  this  intruder,  find  the  latter  produces,  square  yard 
against  square  yard,  six  or  eight  times  as  much  of  available 
eatable  crop. 

None  of  my  friends  who  are  amateur  gardeners  know 
this  variety;  but  a  few  days  since,  I  called  on  Messrs. 
James  Carter  and  Co.,  the  wholesale  seedsmen  of  Holborn, 
and  described  it.  They  gave  me  a  packet  of  what  they  call 
"Perpetual  spinach  beet,"  which,  as  may  be  seen  by  com- 


HOME  GARDENS  FOR  SMOKY  TOWNS.          359 

parison  with  the  seeds  of  those  I  have  here  of  my  own 
growing,  is  probably  the  same.  Messrs.  Carter  and  Co.  tell 
me  that  the  plant  is  very  little  known,  and  the  seed  scarce 
from  want  of  cultivation  and  demand.  I  therefore  step  so 
far  aside  to  describe  and  recommend  it  as  specially  suited 
for  obtaining  large  crops  on  small  areas.* 

I  also  recommend  a  mode  of  growing  cabbages  that  I 
have  found  very  profitable,  viz.,  to  sow  the  seed  broadcast 
in  richly  manured  beds  or  patches  and  leave  the  plants 
crowding  together;  cut  them  down  while  very  young,  with- 
out destroying  the  centre  bud;  let  them  sprout  again  and 
again.  They  thus  yield  a  succession  of  crops,  every  leaf  of 


ich  is  eatable.  This,  instead  of  transplanting  and 
growing  large  plants,  which,  however  desirable  for  sale  in 
the  market,  are  far  less  profitable  for  home  use.  Celery  may 
be  grown  in  like  manner,  and  cut  down  young  and  green 
for  boiling. 

Some  collateral  advantages  may  de  fairly  anticipated  in 
cases  where  the  back-yard  is  fully  enclosed  by  the  canvas. 

In  the  first  place,  the  air  coming  into  the  house  from  the 
back  will  be  more  or  less  filtered  from  the  grimy  irritant 
particles  with  which  our  London  atmosphere  is  loaded, 
besides  obtaining  the  oxygen  given  off  by  the  growing 
plants,  and  the  ozone  which  recent  investigations  have 
shown  to  be  produced  where  aromatic  plants  —  such  as 
kitchen  herbs  —  are  growing.  Lavender,  which  is  very 
hardy,  and  spreads  spontaneously,  might  be  grown  for  this 
purpose. 

Back-doors  might  be  left  open  for  ventilation,  without 
danger  of  intrusion  or  of  slamming  by  gusts  of  wind.  The 
air  thus  admitted  would  be  tempered'both  in  summer  and 
winter.  By  wetting  the  canvas,  which  may  easily  be  done 
by  means  of  a  small  garden  engine,  or  hand  syringe,  the 
exceptionally  hot  summer  days  that  are  so  severely  felt  in 
London  might  be  moderated  to  a  considerable  extent.  The 


*  I  tried  the  seeds  given  to  me  by  Messrs.  Carter,  and  find  them  to 
produce  the  same  plant  as  my  own,  -which  I  still  cultivate  very 
successfully.  I  now  sow  it  in  the  spring  as  a  kitchen  garden 
border. 


360  SCIENCE  IN  SHORT  CHAPTERS. 

air  under  the  canvas  being  cooler  than  that  in  front  would 
enter  from  below,  while  the  warmer  air  would  be  pushed 
upwards  and  outwards  to  the  front. 

Although  such  conservatories  may  be  erected,  as  already 
stated,  by  artisans  or  other  tenants  of  small  houses,  I  do 
not  advocate  dependence  on  this;  but,  on  the  contrary, 
regard  them  as  more  properly  constituting  landlord's 
fixtures,  and  recommend  their  erection  by  owners  of  small 
house  property  in  London  and  other  large  towns.  A  work- 
man who  will  pay  a  trifle  extra  for  such  a  garden,  is  likely 
to  be  a  better  and  more  permanent  tenant  than  one  who  is 
content  with  the  slovenly  squall  or  of  ordinary  back  premises. 

I  base  this  opinion  on  some  experience  of  holding  small 
houses  in  the  outskirts  of  Birmingham  (Talbot  Street, 
Winson  Green.)  These  have  small  gardens,  while  most  of 
those  around  have  none.  They  are  held  by  weekly  tenure, 
and,  during  eighteen  years,  I  have  not  lost  a  week's  rent 
from  voids;  the  men  who  would  otherwise  shift  their  dwell- 
ing when  they  change  workshops,  prefer  to  remain  and 
walk  some  distance  rather  than  lose  their  little  garden 
crops;  and  when  obliged  to  leave,  have  usually  found  me 
another  tenant,  a  friend  who  has  paid  them  a  small  tenant- 
right  premium  for  what  is  left  in  the  garden,  or  for  the 
privilege  of  getting  a  house  with  such  a  garden. 

A  small  garden  is  one  of  the  best  rivals  to  the  fascina- 
tions of  the  tap-room;  the  strongest  argument  in  favor  of 
my  canvas  conservatories,  and  that  which  I  reserve  as  the 
last,  is  that  they  are  likely  to  become  the  poor  man's 
drawing-room,  where  he  may  spend  his  summer  evenings, 
smoke  his  pipe,  contemplate  his  growing  plants,  and  show 
them  in  rivalry  to  his  friends,  rather  than  slink  away  from 
an  unattractive  home  to  seek  the  sensual  excitements  that 
ruin  so  many  of  our  industrious  fellow-countrymen. 

As  above  stated,  I  have  not  been  able  practically  to  test 
the  filtering  capabilities  of  the  canvas,  owing  to  my  residence 
out  of  town,  but  since  the  above  was  written,  i.e.,  on  last 
Wednesday  evening,  I  visited  the  Houses  of  Parliament, 
where,  as  I  had  been  told,  the  ventilation  arrangements 
include  some  devices  for  filteriag  the  air  by  cotton,  wool  or 
otherwise. 


HOME  GARDENS  FOR  SMOKY  TOWNS.          361 

I  was  much  interested  on  finding  that  the  long  experience 
and  many  trials  of  Dr.  Percy  and  his  assistant  engineer,  Mr. 
Prim,  have  resulted  in  the  selection  of  the  identical  material 
which  I  have  chosen,  and  with  which  the  above-described 
experiments  have  been  made.  A  wall  of  such  canvas 
surrounds  a  lower  region  of  the  Houses,  and  all  the  air  that 
is  destined  to  have  the  privilege  of  being  breathed  by 
British  legislators  is  passed  through  this  vertical  screen,  for 
the  purpose  of  separating  from  it  the  sooty  impurities  that 
constitute  the  special  abomination  of  our  metropolitan 
atmosphere,  and  that  of  our  great  manufacturing  towns. 
The  quantity  of  sooty  matter  thus  arrested  is  shown  by  the 
fact  that  it  is  found  necessary  to  lake  the  screens  down  once 
a  week  and  wash  them,  the  wash  water  coming  away  in  a 
semi-inky  condition. 

I  anticipate  that  the  conservatory  filters  will  rapidly  clog, 
and,  therefore,  require  washing.  This  may  easily  be  done 
by  means  of  a  jet  from  a  hand-syringe  directed  from  within 
outwards,  especially  if  the  slope  of  the  roof  is  considerable, 
which  is  to  be  recommended.  The  filtering  screen  of  the 
Houses  of  Parliament  is  made  by  sewing  the  canvas  edges 
together,  to  form  a  large  continuous  area,  then  edging  the 
borders  of  this  with  tape,  and  stretching  it  bodily  on  to  a 
stout  frame.  This  method  may  be  found  preferable  to  that 
which  I  proposed  above,  and  cheaper  than  I  have  estimated, 
as  only  very  light  intermediate  cross-pieces  would  thus  be 
required,  merely  to  prevent  bagging,  the  parliamentary 
quartering  above  described  being  nine  feet  apart  instead  of 
three.  This  would  reduce  the  cost  of  timber  to  about  one 
half  of  the  above  estimate.*  The  perpendicular  walls  of  a 
conservatory,  where  such  are  required,  may  certainly  be 
made  thus,  and  I  think  the  roof  also,  if  the  slope  is  con- 
siderable. Or,  if  in  demand,  the  material  may  be  made  of 
greater  width  than  the  three  feet. 

So  far,  I  have  only  mentioned  back-yards;  but,  besides 
these,  there  are  many  very  melancholy  front  areas,  called 


*  Subsequent  experiments  induce  me  not  to  recommend  this  econ- 
omy, on  account  of  the  bagging  which  results  from  excessive  width 
between  the  frames;  3  feet  should  not  be  exceeded. 


862  SCIENCE  IN  SHORT  CHAPTERS. 

"gardens,"  attached  to  good  houses  in  some  of  the  once 
suburban,  but  now  internal  regions  of  London,  where  the 
houses  stand  some  distance  back  from  the  formerly  rural 
highway.  These  spaces  might  be  cheaply  enclosed  with 
canvas/ and  cultivated  as  kitchen  gardens,  orchard  houses, 
flower  gardens,  or  ferneries,  thus  forming  elegant,  refresh- 
ing, and  profitable  vestibules  between  the  highway  and  the 
house-door,  and  also  serve  as  luxurious  summer  drawing- 
rooms.  The  only  objection  I  foresee  to  these  bright  en- 
closures will  be  their  tendency  to  encourage  the  consump- 
tion of  tobacco. 

The  Discussion  which  followed  the  reading  of  the  preceding 
paper  at  the  Society  of  Arts. 

A  member  asked  if  Mr.  Williams  had  observed  the  effect 
of  wind  and  rain  on  this  material? 

Mr.  W.  P.  B.  Shepheard  said  he  was  interested  in  a  large 
square  in  London,  and  he  had  hoped  to  hear  something 
about  the  cultivation  of  flowers  in  such  places.  Last  year, 
they  tried  the  experiment  with  several  varieties  of  flower 
seeds,  and  they  came  up  and  bloomed  well  in  the  open 
ground  without  any  protection  whatever.  In  most  London 
squares,  the  difficulty  was  to  find  anyone  bold  enough  to 
try  the  experiment  at  all,  and  nothing  but  experience  would 
prove  what  flowers  would  succeed  and  what  would  not. 
They  were  so  successful  last  year  that  several  fine  bouquets 
were  gathered  in  July  and  August,  and  sent  to  some  of  the 
gardening  magazines,  who  expressed  their  astonishment 
that  such  good  results  were  possible  in  the  circumstances. 
If  flowers  would  answer,  there  would,  of  course,  be  more 
encouragement  to  try  vegetables.  One  of  the  practical 
difficulties  which  occurred  to  him,  with  regard  to  this  plan, 
was  that  the  screens  would  be  somewhat,  unsightly,  and 
then  again  they  might  shrink,  from  alteration  in  the 
temperature  and  getting  wet  and  dry.  He  would  repeat, 
however,  that,  for  a  very  small  expense  in  seeds,  a  very 
good  show  of  hardy  annuals  and  perennials  might  be 
obtained  in  July  and  August  evenfin  London. 

Mr.  C.  Cooke  said  a  flower-garden  had  recently  been 
opened  in  Drury  Lane,  on  the  site  of  an  old  churchyard,,  to 


HOME  GARDENS  FOR  SMOKY  TOWNS.          363 

which  children  were  admitted ;  and  he  wished  a  similar 
arrangement  might  be  made  in  some  of  the  squares  in 
crowded  neighborhoods,  such  as  Golden  Square,  and 
especially  in  Lincoln's  Inn  Fields.  There  were  lots  of 
children  playing  about  in  the  streets,  and  he  wished  the 
good  example  set  by  the  Templars  might  be  followed. 

Mr.  Liggins,  as  an  old  member  of  the  Koyal  Horticultural 
Society,  felt  a  great  interest  in  this  subject.  Among  his 
poorer  neighbors  in  the  district  of  Kensington,  cottage  and 
window  gardening  had  been  encouraged  for  some  years  past, 
prizes  having  been  awarded  to  those  who  were  most  success- 
ful, much  to  their  gratification.  This  was  a  novel  idea,  but 
he  felt  quite  sure  that  it  would  enable  those  who  adopted  it 
to  obtain  the  crops  which  had  been  described.  There  were 
many  collateral  advantages  which  it  would  bestow  on  the 
working  classes  if  largely  followed  by  them,  especially  the 
one  mentioned  by  Mr.  Williams,  that  those  who  devoted 
their  spare  time  to  the  cultivation  of  fruit  and  flowers  would 
not  be  so  open  to  the  attractions  of  the  public-house. 
When  traveling  through  the  United  States  some  years  ago, 
he  was  much  struck  with  the  difference  in  appearance  of  the 
houses  in  districts  where  the  Maine  liquor  law  was  in  force, 
and  soon  learned  to  distinguish  where  it  was  adopted  by 
the  clean,  cheerful  look  of  the  workmen's  dwellings,  the 
neatness  of  the  gardens,  and  the  presence  of  trees  and 
flowers  which,  in  other  districts,  were  wanting.  He  was 
not  a  teetotaler  himself,  and  was  not  advocating  such  re- 
strictions, but  he  could  not  help  noticing  the  contrast;  and 
he  felt  sure  that  in  all  our  large  towns  great  progress  in 
civilization  and  morals  would  be  effected  if  such  an  attrac- 
tion were  offered  to  the  working  classes.  He  believed  there 
was  so  much  intelligence  and  good  sense  among  them, 
that  if  they  only  knew  what  could  be  done  in  this  way  they 
would  attempt  it;  and  when  an  Englishman  attempted 
anything,  he  generally  succeeded. 

Mr.  William  Botly  said  they  were  much  indebted  to  Mr. 
Williams  for  having  called  attention  to  this  important  sub- 
ject. He  quite  agreed  with  the  observations  of  the  last 
speaker,  for  his  own  experience  in  building  cottages  showed 
him  that  the  addition  of  a  piece  of  garden  ground  had  an 


364  SCIENCE  IN  SHORT  CHAPTERS. 

excellent  effect  on  the  social,  moral,  and  religious  welfare 
of  the  inmates.  It  kept  them  from  the  public-house,  and 
the  children  who  were  brought  up  to  hoe  and  weed  their 
parents'  gardens  turned  out  the  most  industrious  laborers 
on  his  property.  He  had  known  of  instances  where  houses 
had  been  built  with  flat  concrete  roofs,  and  covered  in  with 
glass,  so  as  to  form  a  conservatory,  in  which  vegetables  and 
salads  grow  very  well,  and  he  believed  the  cost  was  little,  if 
any,  more  than  ordinary  slating. 

The  Chairman  (Lord  Alfred  Churchill)  in  moving  a  vote 
of  thanks  to  Mr.  Williams,  said  there  could  be  no  doubt 
that  if  his  suggestion  were  adopted  it  would  lead  to  great 
economy,  and  have  many  other  attractions  for  the  working- 
classes.  During  the  last  few  years  they  had  heard  a  good 
deal  about  floriculture  in  windows,  and  no  doubt  it  was  an 
excellent  proposal,  but  if  they  could  add  to  this  the  growth 
of  vegetables  it  would  have  economical  advantages  also. 
The  proposal  to  erect  temporary  conservatories  on  the 
roofs  of  some  of  these  small  houses  was  an  admirable  one. 
He  saw  no  reason  why  you  should  not  have  a  peach  tree 
growing  against  many  a  tall  chimney;  you  would  only 
want  a  metal-lined  tub  filled  with  a  good  mold ;  the 
warmth  of  the  chimney  would  aid  in  promoting  the  growth 
of  the  tree,  and  it  could  be  protected  from  the  smoke  and 
frost  by  this  canvas.  One  point  he  should  like  to  know 
was,  whether  the  fabric  would  not  become  rotted  by  the 
weather,  and  perhaps  it  might  be  protected  by  tanning,  or 
some  chemical  preparation.  The  effect  of  the  canvas  in 
maintaining  an  equable  temperature  was  a  great  considera- 
tion ;  the  difference  stated  by  Mr.  Williams,  of  about  five 
degrees  in  winter,  in  many  cases  would  be  just  enough  to 
save  the  life  of  a  plant.  Practical  gardeners  knew  the  value 
of  placing  a  covering  over  a  peach  tree  in  early  spring  to 
keep  off  the  frosts,  and  also  to  protect  it  from  the  attacks 
of  birds.  It  was  also  a  curious  fact  that  even  a  slip  of  wood 
or  slate  a  few  inches  wide,  put  on  the  top  of  a  wall  to  which 
a  fruit  tree  was  nailed,  acted  as  a  protection  from  frost. 
He  trusted  that  Mr.  Williams'  idea  would  find  favor 
among  the  working  classes,  and  thought  it  was  a  subject 
the  Royal  Horticultural  Society  might  well  take  up  and 


HOME  GARDENS  FOR  SMOKY  TOWNS.          365 

offer  prizes  for.  He  hoped  in  a  short  time,  when  that 
Society  had  passed  through  a  crisis  which  was  impending, 
it  might  emerge  in  a  condition  to  devote  attention  to  this 
matter.  It  already  offered  prizes  for  small  suburban  flower- 
shows,  but  had  not  yet  turned  its  attention  to  the  larger 
class  aimed  at  by  Mr.  Williams. 

Mr.  Botly  said  he  had  forgotten  to  mention  that  he  had 
a  friend,  a  very  excellent  gardener,  who  always  loosened  his 
fruit  trees  from  the  wall  for  about  three  weeks  before  the 
time  of  blooming.  The  consequence  was,  they  did  not  get 
so  much  heat  from  the  wall,  and  the  bloom  was  two 
or  three  weeks  later  in  forming.  After  the  spring  frosts, 
the  trees  were  again  nailed  up  close,  and  he  never  failed 
in  getting  an  excellent  crop,  when  his  neighbors  often  had 
none. 

Mr.  Trewby  wished  to  caution  those  who  read  the  paper 
against  using  what  was  commonly  known  as  paperhangers' 
canvas,  because  it  was  made  of  two  materials,  hemp  and 
jute,  and  if  a  piece  of  it  were  put  into  water  it  Avould  soon 
be  nothing  but  a  lot  of  strings,  the  jute  being  all  dissolved. 
It  did  very  well  for  paper-hanging,  but  would  be  quite 
unsuitable  for  this  purpose.* 

The  vote  of  thanks  having  been  passed — 

Mr.  Williams,  in  reply,  said  he  had  had  a  piece  of  this 
canvas  stretched  on  a  frame  exposed  all  the  winter,  and  the 
only  result  was  to  make  it  rather  dirty.  He  stretched  it  as 
tightly  as  he  could  in  putting  it  on,  but  when  it  got  wet  it 
became  still  more  tight,  and  gave  a  little  again  on  becoming 
dry.  It  bore  the  weight  of  the  snow  which  had  fallen  very 
well,  and  two  or  three  spadefuls  had  been  added  to  try  it. 
He  had  a  note  from  Mr.  Prim,  saying  that  at  the  Houses 
of  Parliament  the  screens  last  about  two  sessions,  being 
washed  once  a  week,  and  the  destruction  is  due  to  the 
wringing.  But  there  is  really  no  occasion  for  this,  for  if 


*  I  have  followed  up  Mr.  Trewby's  hint,  and  find  that  more  than 
one  quality  of  scrim  is  made.  The  best,  made  entirely  of  flax,  costs 
rather  more  than  the  2£rf.  stated  iu  the  estimate,  but  it  is  the  cheapest 
practically.  The  best  I  have  seen  is  that  used  in  the  Houses  of 
Parliament. 


366  SCIENCE  IN  SHORT  CHAPTERS. 

you  syringe  the  stuff  well  from  the  inside,  you  make  it 
sufficiently  clear  to  allow  the  air  and  light  to  pass  through, 
and  it  would  probably  last  many  years.  He  had  tried  the 
experiment  of  dipping  it  in  a  very  weak  solution  of  tar,  but 
this  had  the  effect  of  matting  together  the  fine  filaments, 
so  that  it  did  not  act  so  effectually  as  a  strainer.  It  acted 
best  when  wet,  because  the  fine  particles  of  soot  adhered  to 
it,  and  moist  weather  was  just  the  time  when  the  greatest 
quantity  of  soot  fell.  It  might  be  easily  tried  in  London 
squares'to  aid  in  the  growth  of  flowers;  he  found  that  the 
cabbage  plants  which  were  so  protected  throve  remarkably 
well,  and  he  had  no  doubt  that  if  flowers  were  planted  and 
a  screen  put  over  them  until  they  were  ready  to  bloom,  it 
would  be  a  great  advantage.  The  action  of  a  little  pent  on 
the  top  of  a  wall  to  protect  fruit  trees  is  very  simple,  and 
the  explanation  was  afforded  by  the  experiments  of  Dr. 
Wells  on  dew.  The  frosts  which  did  the  greatest  mischief, 
were  due  to  radiation  from  the  ground  on  clear  nights ; 
and  it  would  be  found  that  if  one  thermometer  were  placed 
in  a  garden  under  an  umbrella,  and  another  on  the  open 
ground  near  it,  the  differences  of  temperature  would  be 
very  considerable  ;  on  cloudy  nights  there  was  very  little 
difference.  Last  night  there  was  only  a  difference  of  2°, 
but  a  few  nights  before  it  was  6°.  The  period  of  greatest 
cold  might  not  probably  be  more  than  hour,  but  it  would 
be  sufficient  to  do  a  great  deal  of  mischief,  and  anything 
which  would  check  the  radiation  would  have  the  required 
effect.  In  the  case  of  loosening  the  fruit  trees  from  the 
wall  there  was,  probably,  a  double  action  ;  it  prevented  the 
tree  being  forced  on  by  the  warmth  or  the  wall  in  the  day- 
time, and  also  avoided  the  chilling  effect  at  night,  a  rough 
wall  being  a  good  radiator,  and  sinking  to  a  low  tempera- 
ture. Ho  did  not  think  there  was  much  danger  to  be 
apprehended  from  wind,  because  the  canvas  being  so  open, 
the  wind  would  pass  freely  through  it ;  but  he  had  not  seen 
it  subjected  to  any  violent  gale. 


SOLIDS,  LIQUIDS,  AND  GASES.  367 


SOLIDS,  LIQUIDS,  AND  GASES. 

THE  growth  of  accurate  knowledge  is  continually  narrow- 
ing, and  often  obliterating,  the  broad  lines  of  distinction 
that  have  been  drawn  between  different  classes  of  things. 
I  well  remember  when  our  best  naturalists  regarded  their 
"species"  of  plants  and  animals  as  fundamental  and  invio- 
lable institutions,  separated  by  well-defined  boundaries  that 
could  not  be  crossed.  Darwin  has  upset  all  this,  and  now 
we  cannot  even  draw  a  clear,  sharp  line  between  the  animal 
and  vegetable  kingdoms.  The  chemist  is  even  crossing  the 
boundary  between  these  and  the  mineral  kingdom,  by  re- 
futing the  once  positive  dictum  that  organic  substances 
(i.e.,  the  compounds  ordinarily  formed  in  the  course  of 
vegetable  or  animal  growth)  cannot  be  produced  directly 
from  dead  matter  by  any  chemical  device.  Many  of  such 
organic  compounds  are  now  made  in  the  laboratory  from 
mineral  materials. 

We  all  know,  broadly,  what  are  the  differences  between 
solids,  liquids,  and  gases,  and,  until  lately,  they  have  been 
very  positively  described  as  the  three  distinct  states  or 
modes  of  existence  of  matter.  Mr.  Crookes  suggests  a 
fourth.  I  will  not  discuss  this  at  present,  but  merely  con- 
sider the  three  old-established  claimants  to  distinctive  ex- 
istence. 

A  solid  is  usually  defined  as  a  body  made  up  of  particles 
which  hold  together  rigidly  or  immovably,  in  contradis- 
tinction to  a  fluid,  of  which  the  particles  move  freely  over 
each  other.  "Fluids"  is  the  general  term  including  both 
gases  and  liquids,  both  being  alike  as  regards  the  mobility 
of  their  particles.  At  present,  let  us  confine  our  attention 
to  liquids  and  solids. 

The  theoretical  or  perfect  fluid  which  is  imagined  by  the 
mathematician  as  the  basis  of  certain  abstract  reasonings 
has  no  real  existence.  He  assumes  (and  the  assumption  is 
legitimate  and  desirable,  provided  its  imaginary  character 
is  always  remembered)  that  the  supposed  particles  move 
upon  each  other  with  perfect  freedom,  without  any  friction 
or  other  impediment ;  but,  as  a  mutter  of  fact,  all  liquids 


368  SCIENCE  IN  SHORT  CHAPTERS. 

exert  some  amount  of  resistance  to  their  own  flowing  ;  they 
are  more  or  less  viscous,  have  more  or  less  of  that  sluggish- 
ness in  their  obedience  to  the  law  of  finding  their  own  level 
which  we  see  so  plainly  displayed  by  treacle  or  castor  oil. 

This  viscosity,  added  to  the  friction  of  the  liquid  against 
the  solid  on  which  it  rests,  or  in  which  it  is  enclosed,  may 
become,  even  in  the  case  of  water,  a  formidable  obstacle  to 
its  flow.  Thus,  if  we  make  a  hole  in  the  side  of  a  tank  at 
a  depth  of  16  feet  below  the  surface,  the  water  will  spout 
from  that  hole  at  the  rate  of  32  feet  per  second,  but  if  we 
connect  with  this  hole  a  long  horizontal  pipe  of  the  same 
internal  diameter  as  the  hole,  and  then  observe  the  flow 
from  the  outlet  of  the  pipe,  we  shall  find  its  velocity  visibly 
diminished,  and  we  shall  be  greatly  deceived  if  we  make 
arrangements  for  carrying  swift-flowing  water  thus  to  any 
great  distances. 

Three  or  four  years  ago  an  attempt  was  made  to  super- 
sede the  water-carts  of  London  by  laying  down  on  each  side 
of  the  road  a  horizontal  pipe,  perforated  with  a  row  of  holes 
opening  towards  the  horse-way.  The  water  was  to  be 
turned  on,  and  from  these  holes  it  was  to  jet  out  to  the 
middle  of  the  road  from  each  side,  and  thus  water  it  all. 
I  watched  the  experiment  made  near  the  Bank  of  England. 

Instead  of  spouting  across  the  road  from  all  these  holes, 
as  it  would  have  done  from  any  one  of  them,  it  merely 
dribbled  ;  the  reason  being  that,  in  order  to  supply  them 
all,  the  water  must  run  through  the  whole  of  the  long  pipe 
with  considerable  velocity,  and  the  viscosity  and  friction  to 
be  overcome  in  doing  this  nearly  exhausted  the  whole  force 
of  water-head  pressure.  Many  other  similar  blunders  have 
been  made  by  those  who  have  sought  to  convey  water-power 
to  a  distance  by  means  of  a  pipe  of  such  diameter  as  should 
demand  a  rapid  flow  through  a  long  pipe. 

The  resistance  which  water  offers  to  the  stroke  of  the 
swimmer  or  the  pull  of  the  rower  is  partly  due  to  its  vis- 
cosity, and  partly  to  the  uplifting  or  displacement  of  some 
of  the  water.  If  it  were  perfectly  fluid,  our  movements 
within  it,  and  those  of  fishes,  etc.,  would  be  curiously  dif- 
ferent ;  the  whole  face  of  this  globe  would  be  strangely 
altered  in  many  respects. 


SOLIDS,  LIQUIDS,  AND  OASES. 

I  will  not  now  follow  up  this  idea,  but  leave  it  as  a  sug- 
gestion for  the  reader  to  work  out  for  himself,  by  consider- 
ing what  would  remain  undone  upon  the  earth  if  water 
flowed  perfectly,  without  any  internal  resistance,  or  friction 
upon  the  earth's  surface. 

The  degrees  of  approach  to  perfect  fluidity  vary  greatly 
with  different  liquids. 

Is  there  any  such  a  thing  as  an  absolute  solid,  or  a  body 
that  has  no  degree  of  fluidity,  the  particles  or  parts  of 
which  will  admit  of  no  change  of  their  relative  positions, 
no  movement  upon  each  other  without  fracture  of  the  mass? 
This  would  constitute  perfect  rigidity,  or  the  opposite  to 
fluidity. 

Take  a  piece  of  copper  or  soft  iron  wire,  about  one  eighth 
of  an  inch  in  diameter,  or  thereabouts,  and  bend  it  back- 
wards and  forwards  a  few  times  as  rapidly  as  possible,  but 
without  breaking  it ;  then,  without  loss  of  time,  feel  the 
portion  that  has  been  bent.  It  is  hot— painfully  so— if 
the  experiment  is  smartly  made.  How  may  this  be  ex- 
plained? 

It  is  evident  that  in  the  act  of  bending  there  must  have 
been  a  displacement  of  the  relative  positions  of  the  parti- 
cles of  the  metal,  and  the  force  demanded  for  the  bending 
indicated  their  resistance  to  this  movement  upon  each 
other;  or,  in  other  words,  that  there  was  friction  between 
them,  or  something  equivalent  to  such  internal  friction, 
and  thus  the  mechanical  force  exerted  in  the  bending  was 
converted  into  heat-force. 

Here,  then,  was  fluidity,  according  to  the  above  defini- 
tion; not  perfect  fluidity,  but  fluidity  attended  with  resist- 
ance to  flow,  or  what  \fe  have  agreed' to  call  viscosity.  But 
water  also  offers  such  resistance  to  flow,  or  viscosity,  there- 
fore the  difference  between  iron  or  copper  wire  and  liquid 
water  as  regards  their  fluidity  is  only  a  difference  of  degree, 
and  not  of  kind;  the  demarcation  between  solids  and 
liquids  is  not  a  broad,  clearly-defined  line,  but  a  band  of 
blending  shade,  the  depths  of  tint  representing  varying 
degrees  of  viscosity. 

Multitudes  of  examples  may  be  cited  illustrating  the 
viscosity  of  bodies  that  we  usually  regard  as  types  of  solidity, 


370  SCIENCE  IN  SHORT  CHAPTERS. 

such,  for  example,  as  the  rocks  forming  the  earth's  crust. 
In  the  "  Black  Country"  of  South  Staffordshire,  which  is 
undermined  by  the  great  ten-yard  coal-seam,  cottages, 
chimney-shafts,  and  other  buildings  may  be  seen  leaning 
over  most  grotesquely,  houses  split  down  the  middle  by  the 
subsidence  or  inclination  of  one  side,  great  hollows  in  fields 
or  across  roads  that  were  once  flat,  and  a  variety  of  other 
distortions,  due  to  the  gradual  sinking  of  the  rock-strata 
that  have  been  undermined  by  the  colliery  workings.  In 
some  cases  the  rocks  are  split,  but  usually  the  subsidence  is 
a  bending  or  flowing  down  of  the  rocks  to  fill  up  the 
vacuity,  as  water  fills  a  hollow,  or  "finds  its  own  level." 

I  have  seen  many  cases  of  the  downward  curvature  of 
thereof  of  a  coal-pit,  and  have  been  told  that  in  some  cases 
the  surrounding  pressure  causes  the  floor  to  curve  upwards, 
but  have  not  seen  this. 

Earthquakes  afford  another  example.  The  so-called 
solid  crust  of  the  earth  is  upheaved,  and  cast  into  positive 
billows  that  wave  away  on  all  sides  from  the  centre  of  dis- 
turbance. The  earth-billows  of  the  great  Lisbon  earth- 
quake of  1755  traveled  to  this  country,  and  when  they 
reached  Loch  Lomond,  were  still  of  sufficient  magnitude  to 
raise  and  lower  its  banks  through  a  perpendicular  range  of 
two  feet  four  inches. 

It  is  quite  possible,  or,  I  may  say,  probable,  that  there 
are  tides  of  the  earth  as  well  as  of  the  waters,  and  the 
subject  has  occupied  much  attention  and  raised  some  dis- 
cussion among  mathematicians.  If  the  earth  has  a  fluid 
centre,  and  only  a  comparatively  thin  crust,  as  some  suppose, 
there  must  be  such  tides,  produced  by  the  gravitation  of  the 
moon  and  sun.  * 

Ice  presents  some  interesting  results  of  this  viscosity. 
At  a  certain  height,  varying  with  latitude,  aspect,  etc.,  we 
reach  the  "snow  line" of  mountain  slopes,  above  which  the 
snow  of  winter  remains  unmelted  during  summer,  and,  in 
most  cases,  goes  on  accumulating.  It  soon  loses  its  floccu- 
lent,  flaky  character,  and  becomes  coherent,  clear  blue  ice 
by  the  pressure  of  its  own  weight. 

A  rather  complex  theory  has  been  propounded  to  ex- 
plain this  change—  the  theory  of  regelation — i.e.,  re-freez- 


SOLIDS,  LIQUIDS,  AND  OASES.  371 

ing;  a  theory  which  assumes  that  the  pressure  first  thaws  a 
film  of  ice  at  the  surface  of  contact,  and  that  presently  this 
re-freezes,  and  thus  effects  a  healing  or  general  solidifica- 
tion. Faraday  found  that  two  pieces  of  ice  with  moistened 
surfaces  united  if  pressed  together  when  at  just  about  the 
temperature  of  freezing,  but  not  if  much  colder.  Tyndall 
has  further  illustrated  this  by  taking  fragments  of  ice  and 
squeezing  them  in  a  mould,  whereby  they  became  a  clear, 
transparent  ball,  or  cake.  Schoolboys  did  the  like  long  be- 
fore, when  snowballing  with  snow  at  about  the  thawing 
point.  Such  snow,  as  we  all  remember,  became  converted 
into  stony  lumps  when  firmly  pressed  together.  We  also 
remember  that  in  much  colder  weather  no  such  cohesion 
occurred,  but  our  snowballs  remained  powdery  in  spite  of 
all  our  squeezing. 

I  am  a  sceptic  as  regards  this  theory  of  regelation.  I 
believe  that  the  true  explanation  is  much  simpler;  that  the 
crystals  of  snow  or  fragments  of  ice  in  these  experiments  are 
simply  welded,  as  the  smith  unites  two  pieces  of  iron,  by 
merely  pressing  them  together  when  they  are  near  their 
melting  point.  Other  metals  and  other  fusible  substances 
may  be  similarly  welded,  provided  they  soften  or  become 
sufficiently  viscous  before  fusing. 

Platinum  is  a  good  example  of  this.  It  is  infusible  in  or- 
dinary furnaces,  but  becomes  pasty  before  melting,  and. 
therefore,  one  method  adopted  in  the  manufactore  of  plati- 
num ingots  or  bars  from  the  ore,  is  to  precipitate  a  sort  of 
platinum  snow  (spongy  platinum)  from  its  solution  in  acid, 
and  then  compress  this  metallic  snow  in  red-hot  steel 
moulds  by  means  of  pistons  driven  with  great  force.  The 
flocculent  metal  thus  becomes  a  solid,  coherent  mass,  just 
as  the  flocculent  ice  became  coherent  ice  in  Tyndall's  experi- 
ment or  in  making  hard  snowballs. 

"Wax,  pitch,  resin,  and  all  other  solid  sthat  fuse  gradually, 
cohere,  are  weldable,  or,  in  very  plain  language,  "stick 
together/'  when  near  their  fusing  point. 

I  have  made  the  following  experiment  to  prove  that 
when  this  so-called  regelation  of  snow  or  ice-fragments 
occurs,  the  ice  is  viscous  or  plastic,  like  wax  or  pitch.  A 
strong  iron  squirt,  with  a  cylindrical  bore  of  half  an  inch 


372  SCIENCE  IN  SHORT  CHAPTERS. 

in  diameter,  is  fitted  with  an  iron  piston.  This  piston  is 
driven  forth  by  a  screw  working  in  a  collar  at  one  end  of 
the  squirt.  Into  the  other  end  is  screwed  a  brass  nozzle 
with  an  aperature  about  one  twentieth  of  an  inch  diameter, 
tapering  or  opening  inwards  gradually  to  the  half-inch 
bore. 

Into  this  bore  I  place  snow  or  fragments  of  ice,  then, 
holding  the  body  of  the  squirt  firmly  in  a  vice,  I  work  the 
lever  of  the  screw,  and  thus  drive  forward  the  piston  and 
crush  down  the  snow  or  ice-fragments,  which  presently  be- 
come coherent  and  form  a  half-inch  solid  cylinder  of  clear 
ice.  Applying  still  more  pressure,  this  cylinder  is  forced 
like  a  liquid  through  the  small  orifice  of  the  nozzle  of  the 
squirt,  and  it  jets  or  spouts  out  as  a  thin  stick  of  ice 
like  vermicelli,  or  the  "leads"  of  ever-pointed  pencils, 
for  the  moulding  of  which  the  squirt  was  originally  con- 
structed. 

I  find  that  ice  at  32°  can  thus  be  squirted  more  easily 
than  beeswax  of  the  same  temperature,  and  such  being  the 
case,  I  see  no  reason  for  imagining  any  complex  operation 
of  regelation  in  the  case  of  the  ice,  but  merely  regard  the 
adhesion  of  two  pieces  of  ice  when  pressed  together  as 
similar  to  the  sticking  together  of  two  pieces  of  cobblers'- 
wax,  or  softened  sealing-wax,  or  beeswax,  or  the  welding 
of  iron  or  glass  when  heated  to  their  welding  tempera- 
tures, i.e.,  to  a  certain  degree  of  incipient  fluidity  or  vis- 
cosity. 

If  a  leaden  bullet  be  cut  in  half,  and  the  two  fresh-cut 
faces  pressed  forcibly  together,  they  cohere  at  ordinary  at- 
mospheric temperatures,  but  we  have  no  occasion  for  a  re- 
gelation  theory  here.  The  viscosity  of  the  lead  accounts  for 
all.  At  Woolwich  Arsenal  there  is  a  monster  squirt,  similar 
to  my  little  one.  This  is  charged  with  lead,  and,  by  means 
of  hydraulic  pressure,  the  lead  is  squired  out  of  the  nozzle 
as  a  cylindrical  jet  of  any  required  diameter.  This  jet  or 
stick  of  lead  is  the  material  of  which  the  elongated  cylin- 
drical rifle  bullets  are  now  made. 

But  returning  to  the  point  at  which  we  started,  on  the 
subject  of  ice,  viz.,  its  Alpine  accumulation  above  the 
snow-line.  If  the  snow-fall  there  exceeds  the  amount  that 


SOLIDS,  LIQUIDS,  AND  GA8E8.  373 

is  thawed  and  evaporated,  it  must  either  go  on  growing 
upward  until  it  reaches  the  highest  atmospheric  region 
from  which  it  falls,  or  is  formed,  or  it  must  descend  some- 
how. 

If  ice  can  be  squirted  through  a  syringe  by  mere  hand- 
pressure,  we  are  justified  in  expecting  that  it  would  be 
forced  down  a  hill  slope,  or  through  a  gully,  or  across  a 
plain,  by  the  pressure  of  its  own  weight  when  the  accumu- 
lation is  great.  Such  is  the  case,  and  thus  are  glaciers 
formed. 

They  are,  strictly  speaking,  rivers  or  torrents  of  ice;  they 
flow  as  liquid  water  does,  and  down  the  same  channels  as 
would  carry  the  liquid  surface  drainage  of  the  hills,  were 
rain  to  take  the  place  of  snow.  Like  rivers,  they  flow  with 
varying  speed,  according  to  the  slope;  like  rivers,  their  cur- 
rent is  more  rapid  in  the  middle  than  the  sides;  like  rivers, 
they  exert  their  greatest  tearing  force  when  squeezed 
narrow  thorugh  gullies;  and,  like  rivers,  they  spread  out  into 
lakes  when  they  come  upon  an  open  basin-like  valley,  with 
narrow  outlet. 

The  Justedalsbrae  of  Norway  is  a  great  ice-lake  of  this 
character,  covering  a  surface  of  about  500  square  miles, 
and  pouring  down  its  ice-torrents  on  every  side,  wherever 
there  is  a  notch  or  valley  descending  from  the  table-land  it 
covers.  The  [rate  of  flow  of  such  downponring  glaciers 
varies  from  two  or  three  inches  to  as  many  feet  per  day, 
and  they  present  magnificent  examples  of  the  actual  flu- 
idity or  viscosity  of  an  apparently  solid  mass.  This  vis- 
cosity has  been  disputed,  and  attempts  have  been  made  to 
otherwise  explain  the  motion  of  glaciers;  but  while  it  is 
possible  that  it  may  be  assisted  by  varying  expansion  and 
contraction,  the  downflow  due  to  viscosity  is  now  recog- 
nized as  unquestionably  the  main  factor  of  glacier  motion. 

Cascades  of  ice  may  be  sometimes  seen.  In  the  course 
of  my  first  visit  to  Norway,  I  wandered  alone  over  a  very 
desolate  mountain  region  towards  the  head  of  the  Jnstedal, 
and  unexpectedly  came  upon  a  gloomy  lake,  the  Stygge- 
vand,  which  lies  at  the  foot  of  a  precipice-boundary  of  the 
great  ice-field  above  named.  Here,  the  ice  having  no 
sloping  valley-trough  by  which  to  descend,  poured  over  the 


374  SCIENCE  IN  SHORT  CHAPTERS. 

edge  of  the  precipice  as  a  great  overhanging  sheet  or  cor- 
nice, which  bent  down  as  it  was  pushed  forward,  and  pre- 
sented on  the  convex  side  of  the  sheet  some  fine  blue 
cracks,  or  "crevasses"  as  they  are  called.  These  gradually 
widened  and  deepened,  until  the  overhanging  mass  broke 
off  and  fell  into  the  lake,  on  the  surface  of  which  I  saw  the 
result,  in  the  form  of  several  floating  icebergs  that  had  pre- 
viously fallen. 

Something  like  this,  on  a  small  scale,  may  be  seen  at 
home  on  the  edge  of  a  house  roof,  on  which  there  has  been 
an  accumulation  of  snow;  but,  in  this  case,  it  is  rather 
sliding  than  flowing  that  has  made  the  cornice;  but  its 
down-bending  is  a  result  of  viscosity. 

These  and  a  multitude  of  other  facts  that  might  be 
stated,  many  of  which  will  occur  to  the  reader,  prove 
clearly  enough  that  the  solid  and  liquid  states  of  matter 
are  not  distinctly  and  broadly  separable,  but  are  connected 
by  an  intermediate  condition  of  viscosity. 

We  now  come  to  the  question  whether  there  is  any  simi- 
lar continuity  between  liquids  and  gases.  Ordinary  expe- 
rience decidedly  suggests  a  negative  answer.  We  can  point 
to  nothing  within  easy  reach  that  has  the  properties  of  a 
liquid  and  gaseous  half-and-half;  that  stands  between  gases 
and  liquids  as  pitch  and  treacle  stand  between  solids  and 
liquids. 

Some,  perhaps,  may  suggest  that  cloud-matter—London 
fog,  for  example — is  in  such  an  intermediate  state.  This, 
however,  is  not  the  case.  White  country  fog,  ordinary 
clouds,  or  the  so-called  "steam"  that  is  seen  assuming  cloud 
forms  as  it  issues  from  the  spout  of  a  tea-kettle  or  funnel 
of  a  locomotive,  consists  of  minute  particles  of  water  sus- 
pended in  air,  as  solid  particles  of  dust  are  also  suspended. 
It  has  been  called  "vesicular  vapor,"  on  the  supposition 
that  it  has  the  form  of  minute  vesicles,  like  soap-bubbles 
on  a  very  small  scale,  but  this  hypothesis  remains  unproven. 
London  fog  consists  of  similar  particles,  varnished  with  a 
delicate  film  of  coal-tar,  and  intersprinkled  with  particles 
of  soot. 

In  order  to  clearly  comprehend  the  above-stated  question, 
we  must  define  the  difference  between  liquids  and 


SOLIDS,  LIQUIDS,  AND  GASES.  375 

In  the  first  place,  they  are  both  fluids,  as  already  agreed. 
What,  then,  is  the  essential  difference  between  liquid  flu- 
idity and  gaseous  fluidity?  The  expert  in  molecular  math- 
ematics, discoursing  to  his  kinematical  brethren,  would 
produce  a  tremendous  reply  to  this  question.  He  would 
describe  the  oscillations,  gyrations,  collisions,  mean  free 
paths,  and  mutual  obstructions  of  atoms  and  molecules, 
and,  by  the  aid  of  a  maddening  array  of  symbols,  arrive  at 
the  conclusion  that  gases,  unless  restrained,  expand  of 
their  own  accord,  while  liquids  retain  definite  limits  or  di- 
mensions. 

The  matter-of-fact  experimentalist  demonstrates  the 
same  by  methods  that  are  easily  understood  by  anybody.  I 
shall,  therefore,  both  for  my  own  sake  and  my  readers', 
describe  some  of  the  latter. 

In  the  first  place,  we  all  see  plainly  that  liquids  have  a 
surface,  i.e.,  a  well-defined  boundary,  and  also  that  gases, 
unless  enclosed,  have  not.  But  as  this  may  be  due  to  the 
invisibility  of  the  gas,  we  must  question  it  further.  The 
air  we  breathe  may  be  taken  as  a  type  of  gases,  as  water 
may  of  liquids.  It  has  weight,  as  we  may  prove  by  weigh- 


squeezed  by  all  that  rests  above  it;  thus  the  air  around 
us  is  constrained  air.  It  is  very  compressible,  and  is  ac- 
cordingly compressed  by  the  weight  of  all  the  air  above  it. 
This  being  understood,  let  us  take  a  bottle  full  of  water 
and  another  full  of  air,  and  carry  them  both  to  the  summit 
of  Mont  Blanc,  or  to  a  similar  height  in  a  balloon.  We 
shall  then  have  left  nearly  half  of  the  atmosphere  below, 
and  thus  both  liquid  and  gas  will  be  under  little  more  than 
half  of  the  ordinary  pressure.  What  will  happen  if  we  un- 
cork them  both?  The  liquid  will  still  display  its  definite 
surface,  and  remain  in  the  bottle,  but  not  so  the  gas.  It 
will  overflow  upwards,  downwards,  or  sideways,  no  matter 
how  the  bottle  is  held,  and  if  we  had  tied  an  empty  blad- 
der over  the  neck  before  uncorking,  we  should  fiud  this 
overflow  or  expansion  pf  the  gas  exactly  proportionate  to 
the  removal  of  pressure,  provided  the  temperature  re- 


376  SCIENCE  IN  SHORT  CHAPTERS. 

mained  unaltered.  Thus,  at  just  half  the  pressure  under 
which  a  pint  bottle  was  corked,  the  air  would  measure  ex- 
actly one  quart,  at  one-eighth  of  the  pressure  one  gallon, 
a'nd  so  on. 

"We  cannot  get  high  enough  for  the  latter  expansion,  but 
can  easily  imitate  the  effect  of  further  elevation  by  means 
of  an  air-pump.  Thus,  we  may  put  one  cubic  inch  of  air 
into  a  bladder  of  100  cubic  inches  capacity,  then  place  this 
under  the  receiver  of  an  air-pump,  and  reduce  the  pressure 
outside  the  bladder  to  j^-th  of  its  original  amount.  With 
such  atmospheric  surrounding,  the  one  cubic  inch  of  air 
will  plump  out  the  flaccid  bladder,  and  completely  fill  it. 
The  pumpability  of  the  air  from  the  receiver  shows  that  it 
goes  on  overflowing  from  it  into  the  piston  of  the  pump  as 
fast  as  its  own  elastic  pressure  on  itself  is  diminished. 

Numberless  other  experiments  may  be  made,  all  proving 
that  all  gases  are  composed  of  matter  which  is  not  merely 
incohesive,  but  is  energetically  self-repulsive;  so  much  so, 
that  it  can  only  be  retained  within  any  bounds  whatever  by 
means  of  some  external  pressure  or  constraint.  For  aught 
we  know  experimentally,  the  gaseous  contents  of  one  of 
Mr.  Glaisher's  baloons  would  outstretch  itself  sufficiently 
to  occupy  the  whole  sphere  of  space  that  is  spanned  by  the 
earth's  orbit,  provided  that  space  were  perfectly  vacuous, 
and  the  baloon  were  burst  in  the  midst  of  it,  the  tempera- 
ture of  the  expanding  gas  being  maintained. 

Here,  then,  in  this  self-repulsiveness,  instead  of  self -co- 
hesion, this  absence  of  self-imposed  boundary  or  dimen- 
sions, we  have  a  very  broad  and  well-marked  distinction 
between  gases  and  liquids,  so  broad  that  there  seems  no 
bridge  that  can  possibly  cross  it.  This  was  believed  to  be 
the  case  until  recently.  Such  a  bridge  has,  however,  been 
built,  and  rendered  visible,  by  the  experimental  researches 
of  Dr.  Andrews;  but  further  explanation  is  required  to 
render  this  generally  intelligible. 

Until  quite  lately  it  was  customary  to  divide  gases  into 
two  classes — "  permanent  gases"  and  "condensable  gases," 
or  "vapors."  Gaseous  water  or  steam  was  usually  described 
as  typical  of  the  latter;  oxygen,  hydrogen,  or  nitrogen  of 
the  former.  Earlier  than  this,  many  other  gases 'were  in- 


SOLIDS,  LIQUIDS,  AND  OASES.  377 

eluded  in  the  permanent  list;  but  Faraday  made  a  serious 
inroad  upon  this  classification  when  he  liquefied  chlorine 
by  cooling  and  compressing  it.  Long  after  this,  the  gase- 
ous elements  of  water,  and  the  chief  constituents  of  air, 
oxygen,  hydrogen,  and  nitrogen,  resisted  all  efforts  to  con- 
dense them;  but  now  they  have  succumbed  to  great  pres- 
sure and  extreme  cooling. 

We  thus  arrive  at  a  very  broad  generalization,  viz.,  that 
all  gases  are  physically  similar  to  steam  (I  mean,  of  course, 
"  dry  steam,"  i.e.,  true  invisible  steam,  and  not  the  cloudy 
matter  to  which  the  name  of  steam  is  popularly  given), 
that  they  are  all  formed  by  raising  liquids  above  their  boil- 
ing point,  just  as  steam  is  formed  when  we  boil  water  and 
maintain  the  steam  above  the  boiling-point  of  the  water. 

But  some  liquids  boil  at  temperatiires  far  below  that  at 
which  others  freeze;  liquid  chlorine  boils  at  a  temperature 
below  that  of  freezing  water,  and  liquid  carbonic  acid  be- 
low even  that  of  freezing  mercury,  and  liquid  hydrogen  far 
lower  still.  These  are  cases  of  boiling,  nevertheless,  though 
it  seems  a  paradox  according  to  the  ideas  we  commonly 
attach  to  this  word.  But  such  ideas  are  based  on  our  com- 
mon experience  of  the  properties  of  our  commonest  of 
liquids,  viz.,  water. 

When  water  boils  under  the  conditions  of  our  ordinary 
experience,  the  passage  from  the  liquid  to  the  gaseous  state 
is  a  sudden  leap,  with  no  intermediate  state  of  existence 
that  we  are  able  to  perceive;  and  the  conditions  upon  which 
water  is  converted  into  steam — the  liquid  into  the  gas — 
while  both  are  at  the  bottom  of  our  atmospheric  ocean,  are 
such  as  to  render  an  intermediate  condition  rationally,  as 
well  as  practically,  impossible. 

We  find  that  the  expansive  energy  by  which  the  steam  is 
enabled  to  resist  atmospheric  pressure  is  conferred  upon  it 
by  its  taking  into  itself,  and  utilizing  for  its  expansive  ef- 
forts a  large  amount  of  calorific  energy.  When  any  given 
quantity  of  water  is  converted  into  steam,  under  ordinary 
circumstances,  its  bulk  sudden!}/  becomes  above  1700  times 
greater — a  cubic  inch  of  water  forms  about  a  cubic  foot  of 
steam,  and  nearly  1000  degrees  of  heat  (966'6)  disappears 
as  temperature.  Otherwise  stated,  we  must  give  to  the  cubic 


378  SCIENCE  IN  SHORT  CHAPTERS. 

inch  of  water  at  212°  as  much  heat  as  would  raise  it  to  a 
temperature  of  212  plus  966*6,  or  1,178 -6°,  if  it  remained 
liquid.  This  is  about  the  temperature  of  the  glowing  coals 
of  a  common  fire;  but  the  steam  that  has  thus  taken  enough 
heat  to  make  the  water  red-hot  is  still  at  212° — no  hotter 
than  the  water  was  while  boiling. 

This  heat,  which  thus  ceases  to  exhibit  itself  as  tempera- 
ture, is  otherwise  occupied.  Its  energy  ia  partly  devoted  to 
the  work  of  increasing  the  bulk  of  the  water  to  the  above- 
named  extent,  and  partly  in  conferring  on  the  steam  its 
gaseous  specialty — that  is,  in  overcoming  liquid  cohesion, 
and  substituting  for  it  the  opposite  property  of  internal 
repulsive  energy  which  is  characteristic  of  gases.  My 
reasons  for  thus  defining  and  separating  these  two  func- 
tions of  the  so-called  "  latent "  heat  will  be  seen  when  we 
come  to  the  philosophy  of  the  interesting  researches  of  Dr. 
Andrews. 

As  already  explained,  all  gases  are  now  proved  to  be 
analogous  to  steam,  they  are  matter  expanded  and  rendered 
self-repulsive  by  heat.  All  elementary  matter  may  exist  in 
either  of  the  three  forms — solid,  liquid,  or  gas,  according 
to  the  amount  of  heat  and  pressure  to  which  it  is  subjected. 
I  limit  this  wide  generalization  to  elementary  substances 
for  the  following  reasons: 

Many  compounds  are  made  up  of  elements  so  feebly  held 
together  that  they  become  "  dissociated"  when  heated  to  a 
temperature  below  their  boiling-point;  or,  their  condition 
may  be  otherwise  defined  by  stating  that  the  bonds  of  chemi- 
cal energy,  which  hold  their  elements  together,  are  weaker 
than  the  cohesion  which  binds  and  holds  them  in  the  con- 
dition of  solid  or  liquid,  and  are  more  easily  broken  by  the 
expansive  energy  of  heat. 

To  illustrate  this,  let  us  take  two  common  and  well- 
known  oils — olive  oil  and  turpentine.  The  first  belongs  to 
the  class  of  "  fixed  oils,"  and  second  to  the  "volatile  oils." 
If  we  apply  heat  to  liquid  turpentine,  it  boils,  passes  into 
the  state  of  gaseous  turpentine,  which  is  easily  condensible 
by  cooling  it.  If  the  liquid  result  of  this  condensation  is 
examined,  we  find  it  to  be  turpentine  as  before.  Not  so 
with  the  olive  oil.  Just  as  this  reaches  its  boiling  point, 


SOLIDS,  LIQUIDS,  AND  OASES.  379 

the  heat,  which  would  otherwise  convert  it  into  olive-oil 
vapor,  begins  to  dissociate  its  constituents,  and  if  the  tem- 
peratutre  be  raised  a  little  higher,  we  obtain  some  gases, 
but  these  are  the  products  of  decomposition,  not  gaseous 
olive  oil.  This  is  called  "  destructive"  distillation. 

In  olive  oil,  the  boiling-point  and  dissociation  point  are 
near  to  each  other.  In  the  case  of  glycerine,  these  points 
so  nearly  approximate  that,  although  we  cannot  distil  it  un- 
broken under  ordinary  atmospheric  pressure,  we  may  do  so 
if  some  of  this  pressure  is  removed.  Under  such  diminished 
pressure,  the  boiling-point  is  brought  down  below  the  dis- 
sociation point,  and  condensible  glycerine  gas  comes  over 
without  decomposition. 

Sugar  affords  a  very  interesting  example  of  dissociation, 
commencing  far  below  the  boiling-point,  and  going  on 
gradually  and  visibly,  with  increasing  rapidity  as  the  tem- 
perature is  raised.  Put  some  white  sugar  into  a  spoon,  and 
neat  the  spoon  gradually  over  the  smokeless  gas-flame  or 
spirit-lamp.  At  first  the  sugar  melts,  then  becomes  yellow 
(barley  sugar);  this  color  deepens  to  orange,  then  red,  then 
chestnut-brown,  then  dark  brown,  then  nearly  black  (cara- 
mel), then  quite  black,  and  finally  it  becomes  a  mere  cinder. 
Sugar  is  composed  of  carbon  and  water;  the  heat  dissociates 
this  compound,  separates  the  water,  which  passes  off  as 
vapor,  and  leaves  the  carbon  behind.  The  gradual  deepen- 
ing of  the  color  indicates  the  gradual  carbonization,  which 
is  completed  when  only  the  dry  insoluble  cinder  remains. 
An  appearance  of  boiling  is  seen,  but  this  is  the  boiling  of 
the  dissociated  water,  not  of  the  sugar. 

The  dissociation  temperature  of  water  is  far  above  its 
boiling-point.  It  is  5072°  Fahr.,  under  conditions  corre- 
sponding to  those  which  make  its  boiling-point  212°.  If 
we  examine  the  variations  of  the  boiling-point  of  water,  as 
the  atmospheric  pressure  on  its  surface  varies,  some  curious 
results  follow.  To  do  this  the  reader  must  endure  some 
figures.  They  are  extremely  simple,  and  perfectly  intelli- 
gible, but  demand  just  a  little  attention. 

Following  are  three  columns  of  figures.  The  first  repre- 
sents atmospheres  of  pressure — i.e.,  taking  our  atmospheric 
pressure  when  it  supports  30  inches  of  mercury  in  the  bar- 


380  SCIENCE  IN  SHORT  CHAPTERS. 

ometcr  tube  as  a  unit,  that  pressure  is  doubled,  trebled, 
etc.,  up  to  twenty  times  in  the  first  column.  The  second 
column  states  the  temperature  at  which  water  boils  when 
under  the  different  pressures  thus  indicated.  The  third 
column,  which  is  the  subject  for  special  study  just  now, 
shows  how  much  we  must  rise  the  temperature  of  the  water 
in  order  to  make  it  boil  as  we  go  on  adding  atmospheres  of 
pressure;  or,  in  other  words,  the  increase  of  temperature 
due  to  each  increase  of  one  atmosphere  of  pressure.  The 
figures  are  founded  on  the  experiments  of  Regnault. 

Pressure  in  Temperature,  F.  Rise  of  Temperature 

Atmospheres  for  each  additional 


1  212 

2 249-5  37-5 

3 273-3  .... 23-8 

4 291-2 17-9 

5 306-0 14-8 

6  318-2 12-2 

7  329-6  11-4 

8 339-5 9-9 

9 348-4 8-9 

10  356-6 8-2 

11  364-2  7-6 

12 371-1 6-9 

13  377-8 6-7 

14 384-0 6-2 

15 390-0 ...  6-0 

16 395-4 5-4 

17 400-8 5-4 

18 405-9 51 

19  410-8 4-9 

20 415-4 4-6 

It  may  be  seen  from  tJie  above  that,  with  the  exception 
of  one  irregularity,  there  is  a  continual  diminution  of  the 
additional  temperature  which  is  required  to  overcome  an 
additional  atmosphere  of  pressure,  and  if  this  goes  on  as 
the  pressure  and  temperatures  advance,  we  may  ultimately 
reach  a  curious  condition — a  temperature  at  which  addi- 
tional pressure  will  demand  no  additional  temperature  to 
maintain  the  gaseous  state;  or,  in  other  words,  a  tempera- 
ture may  be  reached  at  which  no  amount  of  pressure  can 
condense  steam  into  water,  or  at  which  the  gaseous  and 
liquid  states  merge  or  become  indifferent. 


/ SOLIDS,  LIQUIDS,  AND  GASES.  381 

But  we  must  not  push  this  mere  numerical  reasoning 
too  far,  seeing  that  it  is  quite  possible  to  be  continually 
approaching  a  given  point,  without  ever  reaching  it,  as 
when  we  go  on  continually  halving  the  remaining  distance. 
The  figures  in  the  above  do  not  appear  to  follow  accord- 
ing to  such  a  law — nor,  indeed,  any  other  regularity.  This 
probably  arises  from  experimental  error,  as  there  are  dis- 
crepancies in  the  results  of  different  investigators.  They 
all  agree,  however,  in  the  broad  fact  of  the  gradation  above 
stated.  Dulong  and  Arago,  who  directed  the  experiments 
of  the  French  Government  Commission  for  investigating 
this  subject,  state  the  pressure  at  20  atmospheres  to  be 
418-4,  at  21=422-9,  at  22=427'3,  at  23  =  431-4,  and  at  24 
atmospheres,  their  highest  experimental  limit,  435 '5,  thus 
reducing  the  rise  of  temperature  between  the  23d  and  24th 
atmospheres  to  4-1. 

If  we  could  go  on  heating  water  in  a  transparent  vessel 
until  this  difference  became  a  vanishing  quantity,  we  should 
probably  recognize  a  visible  physical  change  coincident  with 
this  cessation  of  condensibility  by  pressure;  but  this  is  not 
possible,  as  glass  would  become  red-hot  and  softened,  and 
thus  incapable  of  bearing  the  great  pressure  demanded. 
Besides  this,  glass  is  soluble  in  water  at  these  high  tem- 
peratures. 

If,  however,  we  can  find  some  liquid  with  a  lower  boiling- 
point,  we  may  go  on  piling  atmosphere  upon  atmosphere  of 
elastic  expansive  pressure,  as  the  temperature  is  raised, 
without  reaching  an  unmanageable  degree  of  heat.  Liquid 
carbonic  acid,  which,  under  a  single  atmosphere  of  pressure, 
boils  at  112°  below  the  zero  of  our  thermometer,  may  thus 
be  raised  to  a  temperature  having  the  same  relation  to  its 
boiling-point  that  a  red-heat  has  to  that  of  water,  and  may 
be  still  confined  within  a  glass  vessel,  provided  the  walls  of 
the  vessel  are  sufficiently  thick  to  bear  the  strain  of  the 
elastic  outstriving  pressure.  In  spite  of  its  brittleness 
glass  is  capable  of  bearing  an  enormous  strain  steadily  ap- 
plied, as  may  be  proved  by  trying  to  break  even  a  mere 
thread  of  glass  by  direct  pull. 

Dr.  Andrews  thus  treated  carbonic  acid,  and  the  experi- 
ment, as  I  have  witnessed  its  repetition,  is  very  curious. 


882  SCIENCE  IN  SHORT  CHAPTERS. 

A  liquid  occupies  the  lower  part  of  a  very  strong  glass 
tube,  which  appears  empty  above.  But  this  apparent  void 
is  occupied  by  invisible  carbonic  acid  gas,  evolved  by  the 
previous  boiling  of  the  liquid  carbonic  acid  below.  We 
start  at  a  low  temperature — say  40°  Fahr.  Then  the  tem- 
perature is  raised;  the  liquid  boils  until  it  has  given  off 
sufficient  gas  or  vapor  to  exert  the  full  expansive  pressure 
or  tension  due  to  that  temperature.  This  pressure  stops 
the  boiling,  and  again  the  surface  of  the  liquid  is  be- 
calmed. 

This  is  repeated  at  a  higher  temperature,  and  thus  con- 
tinued until  we  approach  nearly  to  88°  Fahr.,  when  the 
surface  of  the  liquid  loses  some  of  its  sharp  outline.  Then 
88°  is  reached,  and  the  boundary  between  liquid  and  gas 
vanishes;  liquid  and  gas  have  blended  into  one  mysterious 
intermediate  fluid;  an  indefinite  fluctuating  something  is 
there  filling  the  whole  of  the  tube — an  etherealized  liquid 
or  a  visible  gas.  Hold  a  red-hot  poker  between  your  eye 
and  the  light;  you  will  see  an  upflowing  wavy  movement 
of  what  appears  like  liquid  air.  The  appearance  of  the 
hybrid  fluid  in  the  tube  resembles  this,  but  is  sensibly 
denser,  and  evidently  stands  between  the  liquid  and  gas- 
eous states  of  matter,  as  pitch  or  treacle  stands  between 
solid  and  li'quid. 

The  temperature  at  which  this  occurs  has  been  named 
by  Dr.  Andrews  the  "critical  temperature"',  here  the  gas- 
eous and  liquid  states  are  "continuous"  and  it  is  probable 
that  all  other  substances  capable  of  existing  in  both  states 
have  their  own  particular  critical  temperatures. 

Having  thus  stated  the  facts  in  popular  outline,  I  shall 
conclude  the  subject  by  indulging  in  some  speculations  of 
my  own  on  the  philosophy  of  these  general  facts  or  natural 
laws,  and  on  some  of  their  possible  consequences. 

As  already  stated,  the  conversion  of  water .  into  steam 
under  ordinary  atmospheric  pressure  demands  9G6'6°  of 
heat  over  and  above  that  which  does  the  Avork  of  raising 
the  water  to  212°,  or,  otherwise  stated,  as  much  heat  is  at 
work  in  a  given  weight  of  steam  at  212°,  as  would  raise 
the  same  quantity  of  water  to  1178-6°  if  it  remained 
liquid. 


SOLIDS,  LIQUIDS,  AND  OASES. 

James  Watt  concluded  from  his  experiments  that  a  given 
weight  of  steam,  whatever  may  be  its  density,  or,  in  other 
words,  under  whatever  pressure  it  may  exist,  contains  the 
same  quantity  of  heat.  According  to  this,  if  we  reduced 
the  pressure  sufficiently  to  bring  down  the  boiling-point  to 
112°,  instead  of  212°,  the  latent  heat  of  the  steam  thus 
formed  would  be  1066-6°  instead  of  966 -6°,  or  if,  on  the 
other  hand,  we  placed  it  under  sufficient  pressure  to  raise 
the  boiling-point  to  312°,  the  latent  heat  of  the  steam 
would  be  reduced  to  866'6°,  i.e.,  only  866-6°  more  would 
be  required  to  convert  the  water  into  steam.  If  the  boil- 
ing-point were  412°,  as  it  is  between  19  and  20  atmospheres 
of  pressure,  only  766-6°  more  heat  would  be  required,  and 
so  on,  till  we  reached  a  pressure  which  raised  the  boiling- 
point  to  1178-6°;  the  water  would  then  become  steam 
without  further  heating,  i.e.,  the  critical  point  would  be 
reached,  and  thus,  if  Watt  is  right,  we  can  easily  deter- 
mine, theoretically,  the  critical  temperature  of  water.* 

Mr.  Perkins,  who  made  some  remarkable  experiments 
upon  very  high  pressure  steam  many  years  ago,  and  exhibit- 
ed a  steam  gun  at  the  Adelaide  Gallery,  stated  that  red- 
hot  water  does  not  boil;  that  if  the  generator  be  sufficiently 
strong  to  stand  a  pressure  of  60,000  Ibs.  load  on  the  safety, 
valve,  the  water  may  be  made  to  exert  a  pressure  of  56,000 
Ibs.  on  the  square  inch  at  a  cherry-red  heat  without  boil- 
ing. He  made  a  number  of  rather  dangerous  experiments 
in  thus  raising  water  to  a  red-heat,  and  his  assertion  that 
red-hot  water  does  not  boil  is  curious  when  viewed  in  con- 
nection with  Dr.  Andrews'  experiments. 

I  cannot  tell  how  he  arrived  at  this  conclusion,  having 
been  unable  to  obtain  the  original  record  of  his  experi- 
ments, and  only  quote  the  above  second  hand.  It  is 
worthy  of  remark  that  the  temperature  he  names  is  about 
1170°,  or  that  which,  if  Watt  is  right,  must  be  the  criti- 
cal temperature  of  the  water.  Perkins'  red-hot  water 
would  not  boil,  being  then  in  the  intermediate  condition. 

So  fur,  we  have  a  nice  little  theory,  which  not  only  shows 

*  Watt's  own  figure  for  the  latent  heat  of  steam  at  212°  was  950°, 
but  I  adopt  that  which  is  now  generally  accepted. 


384  SCIENCE  IN  SHORT  CHAPTERS. 

how  the  critical  state  of  water  must  be  reached,  but  also 
its  precise  temperature;  but  all  this  is  based  on  the  assump- 
tion that  Watt  made  no  mistake. 

Unfortunately  for  the  simplicity  of  this  theory,  Regnault 
states  that  his  experiments  contradict  those  of  Watt,  and 
prove  that  the  latent  heat  of  steam  does  not  diminish  just 
in  the  same  degree  as  the  boiling-point  is  raised,  but  that 
instead  of  this  the  diminution  of  the  latent  heat  progresses 
30|  per  cent  more  slowly  than  the  rise  of  temperature,  so 
that,  instead  of  the  latent  heat  of  steam  between  boiling- 
points  of  212°  and  312°  falling  from  966-6°  to  866-6°  it 
would  only  fall  to  895 -1°  or  69 -5°  of  latent  heat  for  every 
100°  of  temperature. 

If  this  is  correct,  the  temperature  at  which  the  latent 
heat  of  steam  is  reduced  to  zero  is  much  higher  than 
1178 '6°,  and  is,  in  fact,  a  continually  receding  quantity 
never  absolutely  reached;  but  I  am  not  prepared  to  accept 
these  figures  of  Regnault  as  implicitly  as  is  now  done  in 
text-books  (I  was  nearly  saying  "as  is  now  the  fashion"), 
seeing  that  they  are  not  the  actual  figures  obtained  by  his 
experiments,  but  those  of  his  "  empirical  formulae"  based 
upon  them.  His  actual  experimental  figures  are  very 
irregular;  thus,  between  steam  temperature  of  171*6°  and 
183 '2°  a  difference  of  11-6°,  the  experimental  difference  in 
the  latent  heat  came  out  as  4 '7°;  between  steam  tempera- 
ture of  183-2°  and  194-8°,  or  11 -6°  again,  the  latent  heat 
difference  is  tabulated  as  8-0°. 

Regnault's  experiments  were  not  carried  to  very  high  tem- 
peratures and  pressures,  and  indicate  that  as  these  advance 
the  deviation  from  Watt's  law  diminishes,  and  may  finally 
vanish  at  about  1500°  or  1600°,  where  the  latent  heat 
would  reach  zero,  and  there,  according  to  the  above,  the 
critical  temperature  would  be  reached.  Any  additional  heat 
applied  after  this  will  have  but  one  function  to  perform, 
viz.,  the  ordinary  work  of  increasing  the  bulk  of  the  heated 
body  without  doing  anything  further  in  the  way  of  confer- 
ring upon  it  any  new  self-repulsive  properties. 

Our  notions  of  solids,  liquids,  and  gases  are  derived  from 
our  experiences  of  the  state  of  matter  here  upon  this  earth. 
Could  we  be  removed  to  another  planet,  they  would  be  cu- 


SOLIDS,  LIQUIDS,  AND  GASES.  385 

riously  changed.  On  Mercury  water  would  rank  as  one  of 
the  condensible  gases;  on  Mars,  as  a  fusible  solid;  but  what 
on  Jupiter? 

Recent  observations  justify  us  in  regarding  this  as  a 
miniature  sun,  with  an  external  envelope  of  cloudy  matter, 
apparently  of  partially  condensed  water,  but  red-hot,  or 
probably  still  hotter  within.  His  vaporous  atmosphere  is  evi- 
dently of  enormous  depth,  and  the  force  of  gravitation  being 
on  his  visible  outer  surface  two  and  a  half  times  greater  than 
that  on  our  earth's  surface,  the  atmospheric  pressure  in  de- 
scending below  this  visible  surface  must  soon  reach  that  at 
which  the  vapor  of  water  would  be  brought  to  its  critical 
condition.  Therefore  we  may  infer  that  the  oceans  of  Ju- 
piter are  neither  of  frozen  liquid  nor  gaseous  water,  but  are 
oceans  or  atmospheres  of  critical  water.  If  any  fish-birds 
swim  or  fly  therein  they  must  be  very  critically  organized. 

As  the  whole  mass  of  Jupiter  is  three  hundred  times 
greater  than  that  of  the  earth,  and  its  compressing  energy 
towards  the  centre  proportional  to  this,  its  materials,  if  sim- 
ilar to  those  of  the  earth  and  no  hotter,  would  be  consider- 
ably more  dense,  and  the  whole  planet  would  have  a  higher 
specific  gravity;  but  we  know  by  the  movement  of  its  satel- 
lites that,  instead  of  this,  its  specific  gravity  is  less  than  a 
fourth  of  that  of  the  earth.  This  justifies  the  conclusion 
that  it  is  intensely  hot,  for  even  hydrogen,  if  cold,  would 
become  denser  than  Jupiter  under  such  pressure. 

As  all  elementary  substances  may  exist  as  solids,  liquids, 
or  gases,  or  critically,  according  to  the  conditions  of  tem- 
perature and  pressure,  I  am  justified  in  hypothetical!}7  con- 
cluding that  Jupiter  is  neither  a  solid,  a  liquid,  nor  a  gaseous 
planet,  but  a  critical  planet,  or  an  orb  composed  internally 
of  dissociated  elements  in  the  critical  state,  and  surrounded 
by  a  dense  atmosphere  of  their  vapors,  and  those  of  some 
of  their  compounds,  such  as  water.  The  same  reasoning 
applies  to  Saturn  and  the  other  large  and  rarefied  planets. 

The  critical  temperature  of  the  dissociated  elements  of 
the  sun  is  probably  reached  at  the  base  of  the  photosphere, 
or  that  region  revealed  to  us  by  the  sun-spots.  When  I 
wrote  "  The  Fuel  of  the  Sun,"  thirteen  or  fourteen  years 
ago,  I  suggested,  on  the  above  grounds,  the  then  heretical 


386  SCIENCE  IN  SHORT  CHAPTERS. 

idea  of  the  red-heat  of  Jupiter,  Saturn,  Uranus,  and  Nep- 
tune,  and  showed  that  all  sucli  compounds  as  water  must 
be  dissociated  at  the  base  of  the  sun's  atmosphere ;  but 
being  then  unacquainted  with  the  existence  of  this  critical 
state  of  matter,  I  supposed  the  dissociated  elements  to  exist 
as  gases  with  a  small  solid  nucleus  or  kernel  in  the  centre. 

Applying  now  the  researches  of  Dr.  Andrews  to  the  con- 
ditions of  solar  existence,  as  I  formerly  applied  the  disso- 
ciation researches  of  Deville,  I  conclude  that  the  sun  has 
no  nucleus,  either  solid,  liquid,  or  gaseous,  but  is  composed 
of  dissociated  matter  in  the  critical  state,  surrounded,  first, 
by  a  flaming  envelope  due  to  the  re-combination  of  the  dis- 
sociated matter,  and  outside  of  this  another  envelope  of 
vapors  due  to  this  combination. 


MURCHISON    AND    BABBAGE. 

THE  curious  contrast  of  character  presented  by  these  two 
eminent  men,  and  the  very  different  course  of  their  lives, 
conveys  a  striking  lesson  to  all  those  superficial  thinkers 
and  unthinking  talkers  who  make  sweeping  generalizations 
concerning  human  character;  who  assume  as  a  matter  of 
course  that  any  man  who  writes  poetry  must  be  merely  a 
dreamer  of  day-dreams,  incapable  of  transacting  any  prac- 
tical daily  business,  and  not  at  all  reliable  in  money  matters; 
whose  eyes  are  always  "in  a  fine  frenzy  rolling";  that  lie 
is,  in  short,  a  sort  of  amiable,  harmless  lunatic.  All  actors, 
according  to  such  people,  are  dissipated  spendthrifts;  and 
if  Sims  Beeves,  or  any  other  public  performer,  is  prevented 
by  delicate  larynx  or  other  indisposition  from  appearing, 
they  look  knowing,  shrug  their  shoulders,  wink  wisely,  and 
assume,  without  the  faintest  shadow  of  evidence,  that  he  is 
drunk. 

In  like  manner  they  set  up  a  typical  philosopher  of  their 
own  manufacture,  and  attribute  his  imaginary  character  to 
all  who  devote  themselves  to  science.  Their  philosopher  is 
a  musty,  dried-up,  absent-minded  pedant,  whose  ordinary 


MURCHISON  AND  BABBAGE.  387 

conversation  is  conducted  in  words  of  seven  syllables,  who 
is  always  lost  in  profound  abstractions;  takes  no  interest  in 
common  things;  regards  music,  dancing,  play-acting,  poetry, 
and  every  cheerful  pursuit  as  frivolous  and  contemptible — 
a  creature  who  never  makes  a  joke,  seldom  laughs,  and  who 
in  matters  of  business  is  even  more  incapable  than  the  poet.  • 

The  singular  contrast  of  character  presented  by  Babbage 
and  Murchison  affords  at  once  a  most  complete  "refutation 
of  such  generalizations.  Here  were  two  men,  both  philoso- 
phers, one  the  very  type  of  amiability,  suavity,  and  all  con- 
ceivable polish,  the  very  perfection  of  a  courtier,  but  differ- 
ing from  the  vulgar  courtier  of  the  Court  in  this  respect, 
that  his  high-toned  courtesy  was  not  bestowed  upon  kings 
only,  but  also  upon  all  his  human  brethren,  and  with  especial 
gracefulness  upon  those  whose  rank  was  below  his  own. 

I  doubt  whether  there  is  any  man  now  living,  or  has 
lived  during  this  generation,  that  could  equal  Sir  Roderick 
Murchison  in  the  art  of  distributing  showers  of  compliments 
upon  a  large  number  of  different  people  in  succession,  and 
making  each  recipient  delightfully  satisfied  with  himself. 
In  his  position  as  Chairman  to  the  Geological  Section  of  the 
British  Association,  he  did  this  with  marvelous  tact,  with- 
out the  least  fulsomeness  or  repetition,  or  any  display  of 
patronizing.  Every  man  who  read  a  paper  before  that  section 
was  better  than  ever  satisfied  with  the  great  merits  and  vast 
importance  of  his  communication,  after  hearing  the  Chair- 
man's comments  upon  it.  None  but  a  most  -detestably 
strong-minded  and  logical  brute  could  resist  the  insinuating 
flattery  of  Sir  Roderick. 

How  different  was  poor  Babbage!  Who  that  attends  any 
sort  of  scientific  gatherings  has  not  seen  Sir  Roderick?  but 
who  in  the  world,  excepting  the  organ-grinders  and  the 
police  magistrate  has  ever  seen  Babbage,  or  even  his  por- 
trait? What  a  contrast  between  the  seclusion  and  the 
public  existence;  between  the  hedgehog  bristles  and  the 
velvet  softness,  of  the  one  and  the  other! 

Those  who  were  on  intimate  terms  with  Babbage  (I  have 
never  met  or  heard  of  such  a  person)  coiild  probably  tell  us 
that  all  his  irritability  and  roughness  were  outside,  and  ihat, 
in  the  absence  of  organ-grinders,  he  was  a  kind  and  amiable 


388  SCIENCE  IN  SHORT  CHAPTERS. 

gentleman;  but,  even  admitting  this,  the  contrast  between 
the  two  philosophers  is  as  great  as  could  well  be  found  be- 
tween any  two  men  following  the  most  widely  divergent 
studies  or  professions. 

Those  who  would  reply  that  mathematics  and  geology 
are  such  different  studies  have  only  to  go  a  little  further 
back  on  the  death-roll,  and  they  will  find  the  name  of  De 
Morgan,  a  pure  mathematician,  like  Babbage.  He  was  a 
man  of  exuberant  fun  and  humor,  and  so  far  from  hating 
music  of  either  a  humble  or  pretentious  character,  was  a 
highly  accomplished  musician,  both  theoretical  and  practi- 
cal, and  if  we  are  to  believe  confidential  communications, 
one  of  his  favorite  instruments  was  the  penny  whistle,  on 
which  he  was  a  most  original  and  peculiar  perfojmer. 

I  had  not  intended  to  reprint  the  above,  which  was  writ- 
ten just  after  the  death  of  Murchison  and  Babbage,  but  the 
comments  that  have  recently  followed  the  death  of  Darwin 
induce  me  to  do  so. 

Many  have  expressed  their  surprise  at  the  unanimous 
expressions  of  Darwin's  friends  concerning  the  geniality  of 
his  disposition,  his  gentleness,  cheerfulness;  his  genuine 
humility  and  simplicity  of  character. 

A  third  type  of  character  is  here  presented,  and  that 
which  corresponds  most  correctly  with  the  true  ideal  of  a 
modern  philosopher,  also  represented  by  that  great-  master 
of  experimental  science,  Faraday.  In  both  of  these  there 
was  the  full  measure  of  Murchison's  amiability,  but  with- 
out the  courtly  polish  of  the  ex-soldier.  Philosophic  med- 
itation and  close  application  to  original  research  may,  and 
often  does,  induce  a  certain  degree  of  shyness  due  to  a  con- 
sciousness of  the  social  disqualification  which  arises  from 
that  inability  to  fulfil  all  the  demands  for  small  attentions 
which  constitute  conventional  politeness;  a  disability  due 
to  habits  of  consecutive  thought  and  mental  abstraction. 

A  sensitive  and  amiable  man  would  suffer  much  pain  on 
finding  that  he  had  neglected  to  supply  the  small  wants  of 
the  lady  sitting  next  to  him  at  a  dinner  party,  and  would 
withdraw  himself  from  the  risk  of  repeating  such  unwit- 
ting rudeness.  This  holding  back  from  ordinary  society, 
though  really  due  to  a  conscientious  sense  of  social  duty 


ATMOSPHERE  versus  ETHER 

and  tender  regard  f6r  the  feelings  of  others,  is  too  often  re- 
ferred to  a  churlish  unsociality  or  arrogant  assumption  of 
superiority. 

If  Newton  really  did  mistake  the  lady's  finger  for  a 
tobacco-stopper,  depend  upon  it  the  pain  he  suffered  was 
far  more  acute  than  that  which  he  inflicted,  and  was  suf- 
fered over  and  over  again  whenever  the  incident  was  recol- 
lected. 


ATMOSPHERE  versus  ETHER. 

ONE  of  the  most  remarkable  meteors  of  which  we  have  a 
reliable  record  appeared  on  February  6,  1818.  Several  ac- 
counts of  it  were  published,  the  fullest  being  that  in  The 
Gentleman's  Magazine  of  the  time.  (I  may  here  add,  pa- 
renthetically, that  one  reason  why  I  have  especial  pleasure-in 
writing  these  notes  is  that  they  contribute  something 
towards  the  restoration  of  the  ancient  status  of  this  maga- 
zine, which  was  at  one  time  the  only  English  serial  that 
ventured  upon  any  notable  degree  of  exposition  of  popular 
science.) 

Upon  the  data  supplied  by  this  account,  Mr.  Joule  has 
calculated  the  height  of  the  meteor  to  have  been  61  miles 
above  the  surface  of  the  earth,  and  he  states  that  "this 
meteor  is  one  of  the  few  that  have  been  seen  in  the 
.daytime,  and  is  also  interesting  as  having  been  one  of  the 
first  whose  observation  afforded  materials  for  the  estima- 
tion of  its  altitude."  It  was  seen  in  the  neighborhood  of 
Cambridge  at  2  P.M.,  also  at  Swaffham  in  Norfolk,  and  at 
Middleton  Cheney  near  Banbury.  The  distance  between 
this  and  Cambridge  is  sufficient  to  afford  a  measurement 
of  its  height,  provided  its  position  above  the  horizon  at 
both  places  was  determined  with  tolerable  accuracy. 

According  to  the  orthodox  text-books,  the  atmosphere  of 
this  earth  terminates  at  a  height  of  about  45  or  50  miles, 
or,  if  not  absolutely  ended  there,  it  ceases  to  be  of  appreci- 
able density  anywhere  above  this  elevation. 

But  here  we  have  a  fact  which  flatly  contradicts  the  cal- 


390  SCIENCE  IN  SHORT  CHAPTERS. 

dilation.  At  61  miles  above  the  earth's  surface  there  must 
be  atmospheric  matter  of  sufficient  density  to  offer  to  the 
passage  of  this  meteor  through  it  an  amount  of  resistance 
which  produced  an  intense  white  heat,  visible  by  its  lumi- 
nosity in  broad  daylight. 

In  the  above-quoted  paper,  read  by  Mr.  Joule  before  the 
Manchester  Literary  and  Philosophical  Society  on  Decem- 
ber 1,  1863,  he  refers  to  subsequent  observations  and  esti- 
mates 116  miles  as  "the  elevation  at  which  meteors  in 
general  are  first  observed" — i.e.,  where  our  atmosphere  is 
sufficiently  dense  to  generate  a  white-heat  by  the  resistance 
it  offers  to  the  rapidly  flying  meteor. 

It  is  curious  to  observe  how,  in  dealing  with  actual  phys- 
ical facts,  a  mathematician  of  the  solid  practical  character 
of  Joule  becomes  compelled  to  practically  throw  overboard 
the  orthodox  theory  of  limited  atmospheric  extension. 
Here,  in  making  his  calculations  of  the  resistance  of  at- 
mospheric matter  at  this  elevation,  be  bases  them  on  the 
assumption  of  a  decrease  of  density  at  the  rate  of  "one 
quarter  for  every  seven  miles,"  and  indicates  no  limit  at 
which  this  rate  shall  vary.  Very  simple  arithmetic  is  suffi- 
cient to  show  that  this  leads  us  to  the  unlimited  atmos- 
pheric extension,  for  which  I  have  contended  we  may  go 
on  for  ever  taking  off  a  quarter  at  every  seven  miles,  and 
there  will  still  remain  the  three  quarters  of  the  quantity 
upon  which  we  last  operated,  or,  more  practically  stated, 
we  shall  thus  go  on  seven  after  seven  until  we  reach  the 
boundaries  of  the  atmospheric  grasp  of  the  gravitation  of 
some  other  sphere. 

Surely  the  time  has  arrived  for  the  full  reconsideration 
of  this  fundamental  question  of  whether  the  universe  is 
filled  with  atmospheric  matter  or  is  the  vacuum  of  the  mo- 
lecular mathematicians  plus  the  imaginary  "ether,"  which 
has  been  invented  by  its  mathematical  creators  only  to  ex- 
tricate them  from  the  absurd  dilemma  into  which  they  are 
plunged  when  they  attempt  to  explain  the  transmission  of 
light  and  heat  by  undulations  traveling  through  space 
containing  nothing  to  undulate. 

They  have  filled  it  with  immaterial  matter  evolved  en- 
tirely from  their  own  consciousness,  which  they  have  gra- 


ATMOSPHERE  versus   ETHER.  391 

tuitously  endowed  with  whatever  properties  are  required 
for  the  fitting  of  their  theories — properties  that  are  self- 
contradictory  and  without  any  counterpart  in  anything 
seen  or  known  outside  of  the  fertile  imagination  of  these 
reckless  theorists. 

We  know  of  nothing  that  can  penetrate  every  form  of 
matter  without  adding  either  to  its  weight  or  its  bulk;  we 
know  of  nothing  that  can  communicate  motion  to  ponder- 
able matter  without  itself  being  ponderable — i.e.,  having 
the  primary  property  of  matter,  viz.,  mass,  or  weight,  and 
consequent  vis  viva  when  moving;  we  know  of  nothing 
that  can  set  bodies  in  motion  without  proportionally  resist- 
ing the  motion  of  bodies  through  it;  and  if  the  waving  of 
the  ether  is  (as  Tyndall  describes  it)  "as  real  and  as  truly 
mechanical  as  the  breaking  of  sea-waves  upon  the  shore," 
the  material  of  the  breakers  must  be  like  the  "jelly"  to 
which  he  compares  it,  and  have  some  viscosity,  or  resistance 
to  penetration,  or  pushing  aside. 

We  have  not  a  shadoAv  of  direct  evidence  of  the  existence 
of  the  "interatomic"  spaces  occupied  by  the  other,  and  in 
the  midst  of  which  the  atoms  are  made  to  theoretically 
swing,  nor  even  of  the  existence  of  the  atoms  themselves. 

The  "ether"  of  to-day,  with  its  imaginary  penetration 
and  its  material  action  without  material  properties,  has 
merely  taken  the  place  of  the  equally  imaginary  phlogiston, 
caloric,  electric,  and  magnetic  fluids,  the  "imponderables" 
of  the  past.  I  have  little  doubt  that  ere  long  the  modern 
modification  of  these  physical  superstitions  will  share  their 
fate,  and  AVC  shall  all  adopt  the  simple  conception  that 
heat,  light,  end  electricity  are,  like  sound,  merely  trans- 
missible states  or  affections  of  matter  itself  regarded 
bodily,  as  it  is  seen  and  felt  to  exist. 

This  may  possibly  throw  a  good  many  mathematicians 
out  of  work — or  into  more  useful  work;  but,  however  that 
may  be,  it  will  .certainly -aid  the  general  diffusion  of  science 
as  the  intellectual  inheritance  of  every  human  being.  At 
present  the  explanations  of  the  simple  phenomena  of  light 
and  heat  are  incomparably  more  difficult  to  understand 
and  to  account  for  than  the  facts  which  they  attempt  to 
elucidate. 


392  SCIENCE  IX  SHORT  CHAPTERS. 


A  NEGLECTED  DISINFECTANT. 

WHEX  the  household  of  our  grandmothers  was  threatened 
with  infection,  the  common  practice  was  to  sprinkle  brim- 
stone on  a  hot  shovel  or  on  hot  coals  on  a  shovel,  and  carry 
the  burning  result  through  the  house.  But  now  this  sim- 
ple method  of  disinfecting  has  gone  out  of  fashion  with- 
out any  good  and  sufficient  reason.  The  principal  reason 
is  neither  good  nor  sufficient,  viz.,  that  nobody  can  patent 
it  and  sell  it  in  shilling  and  half-crown  bottles". 

On  September  18th  last,  M.  d'Abbadie  read  a  paper  at 
the  Academy  of  Sciences  on  "  Marsh  Fevers,"  and  stated 
that  in  the  dangerous  regions  of  African  river  mouths  im- 
munity from  such. fevers  is  often  secured  by  sulphur  fumi- 
gations on  the  naked  body.  Also  that  the  Sicilian  workers 
in  low  ground  sulphur  mines  suffer  much  less  than  the  rest 
of  the  surrounding  population  from  intermittent  fevers. 
M.  Fouque  has  shown  that  Zephyria  (on  the  volcanic  island 
of  Milo  or  Melos,  the  most  westerly  of  the  C}'clades),  which 
had  a  population  of  40,000  when  it  was  the  centre  of  sul- 
phur-miuing  operations,  became  nearly  depopulated  by 
marsh  fever  when  the  sulphur-mining  was  moved  -farther 
east,  and  the  emanations  prevented  by  a  mountain  from 
reaching  the  town.  Other  similar  cases  were  stated. 

It  is  well  understood  by  chemists  that  bleaching  agents 
are  usually  good  disinfectants;  that  which  can  so  disturb 
an  organic  compound  as  to  destroy  its  color,  is  capable  of 
either  arresting  or  completing  the  decompositions  that 
produce  vile  odors  and  nourish  the  organic  germs  or  fer- 
ments which  usual  accompany,  or,  as  some  affirm,  cause 
them.  Sulphurous  acid  is,  next  to  hypochlorous  acid,  one 
of  the  most  effective  bleaching  agents  within  easy  reach. 

I  should  add  that  sulphurous  acid  is  the  gas  that  is 
directly  formed  by  burning  sulphur.  By  taking  up  an- 
other dose  of  oxygen  it  becomes  sulphuric  acid,  which, 
combined  with  water,  is  oil  of  vitriol.  The  bleaching  and 
disinfecting  action  of  the  sulphurous  acid  is  connected  with 
its  activity  in  appropriating  the  oxygen  which  is  loosely 
held  or  being  given  off  by  organic  matter.  Chlorine  and 


ANOTHER  DISINFECTANT.  393 

hypochlorous  acid  (which  is  still  more  effective  than  chlo- 
rine itself)  act  in  the  opposite  way,  so  do  the  permanga- 
nates, such  as  Oondy's  fluid,  etc.  They  supply  oxygen  in 
the  presence  of  water.  It  is  curious  that  opposite  actions 
should  produce  like  results.  A  disquisition  on  this  and  its 
suggestions  would  carry  me  beyond  the  limits  of  a  note. 


ANOTHER  DISINFECTANT. 

THE  above-named  disinfectants  are  objectionable  on  ac- 
count of  their  own  odors  and  their  corrosive  action.  Both 
sulphurous  acid  and  hypochlorous  acid  (the  active  principle 
of  the  so-called  "chloride  of  lime")  have  a  disagreeable 
habit  of  rusting  iron  and  suggesting  antique  green  bronzes 
by  their  action  on  brass  ornaments.  Under  serious  condi- 
tions this  should  be  endured,  but  in  many,  cases  where  the 
danger  is  not  already  developed,  the  desired  end  may  be 
attained  without  these  annoyances. 

Sulphate  of  copper,  which  is  not  patented  or  "  brought 
out"  by  a  limited  company,  may  be  bought  at  its  fair 
retail  value  of  6d.  or  less  per  Ib.  (the  oil-shop  name  for  it 
is  "  blue  vitriol"),  in  crystals,  readily  soluble  in  water. 

I  have  lately  used  it  in  the  case  of  a  trouble  to  which 
English  households  are  too  commonly  liable,  and  one  that 
has  in  many  cases  done  serious  mischief.  The  stoppage  of 
a  soil-pipe  caused  the  overflow  of  a  closet,  and  a  consequent 
saturation  of  floor  boards,  that  in  time  would  probably 
have  developed  danger  by  nourishing  and  developing  those 
germs  of  bacteria,  bacilli,  etc.,  which  abound  in  the  air, 
and  are  ready  to  increase  and  multiply  wherever  their  un- 
savory food  abounds. 

By  simply  mopping  the  floor  with  a  solution  of  these 
green  crystals,  and  allowing  it  to  soak  well  into  the  pores  of 
the  wood,  they  cease  to  become  a  habitat  for  such  microsco- 
pic abominations.  The  copper-salt  poisons  the  poisoners. 

Dr.  Burg  goes  so  far  as  to  recommend  that  building  ma- 
terials, articles  of  furniture,  and  clothing,  etc.,  should  be 


394  SCIENCE  IN  SHORT  CHAPTERS. 

injected  with  sulphate  of  copper,  in  order  to  avert  infec- 
tion, and  in  support  of  this  refers  to  the  immunity  of 
workers  in  copper  from  cholera,  typhoid  fever,  and  infec- 
tious diseases  generally. 

I  agree  with  him  to  the  extent  of  suggesting  the  desira- 
bility of  occasionally  mopping  house  floors  with  this  solu- 
tion. Its  visible  effects  on  the  wood  are  first  to  stain  it 
with  a  faint  green  tinge  which  gradually  tones  down  to  a 
brown  stain,  giving  to  deal  the  appearance  of  oak,  a  change 
which  has  no  disadvantage  from  an  artistic  point  of  view. 
If  the  wood  is  already  tainted  with  organic  matter  capable 
of  giving  off  sulphurated  hydrogen,  the  darkening  change 
is  more  rapid  and  decided,  owing  to  the  formation  of  sul- 
phide of  copper. 

The  solution  of  sulphate  should  not  be  put  into  iron  or 
zinc  vessels,  as  it  rapidly  corrodes  them,  and  deposits  a 
non-adherent  film  of  copper.  It  will  even  disintegrate  com- 
mon earthenware,  by  penetrating  the  glaze,  and  crystalliz- 
ing within  the  pores  of  the  ware,  but  this  is  a  work  of  time 
(weeks  or  months).  Stoneware  resists  this,  and  wooden 
buckets  may  be  used  safely.  It  is  better  to  keep  the  crys- 
tals and  dissolve  when  required.  Ordinary  earthenware 
may  be  used  with  impunity  if  washed  immediately  after- 
wards. 


ENSILAGE. 

This  subject  has  been  largely  expounded  and  discussed 
lately  in  the  Times  and  other  newspapers.  As  most  of  my 
readers  are  doubtless  aware,  it  is  simply  a  substitute  for 
haymaking,  by  digging  pits,  paving  and  building  them 
round  with  stone  or  concrete,  then  placing  the  green  fod- 
der therein  and  covering  it  over  with  sufficient  earth  to 
exclude  the  air. 

We  are  told  that  very  inferior  material  (such  as  coarse 
maize  grass  mixed  with  chaff)  when  thus  preserved  gives 
better  feeding  and  milking  results  than  good  English  hay. 

I  may  mention  a  yery  humble  experience  of   my  own 


ENSILAGE.  395 

that  bears  upon  this.  When  a  boy,  I  was  devoted  to  silk- 
worms, and  my  very  small  supply  of  pocket-money  was 
over-taxed  in  the  purchase  of  exorbitantly  small  penny- 
worths of  mulberry  leaves  at  Covent  Garden.  But  a  friend 
in  the  country  had  a  mulberry  tree,  and  at  rather  long  in- 
tervals I  obtained  large  supplies,  which,  in  spite  of  all  my 
careful  wrapping  in  damp  cloths,  became  rotted  in  about 
ten  days.  I  finally  tried  digging  a  hole  and  burying  them. 
They  'remained  fresh  and  green  until  all  my  silkworms 
commenced  the  working  and  fasting  stage  of  their  exist- 
ence. This  was  ensilage  on  a  small  scale. 

The  correspondence  in  the  newspapers  has  suggested  a 
number  of  reasons  why  English  farmers  do  not  follow  the 
example  of  their  continental  neighbors  in  this  respect; 
climate,  difference  of  grasses,  etc.,  etc.,  are  named,  but  the 
real  reason  why  this  is  commercially  impossible,  and  farm- 
ing, properly  so  called,  is  becoming  a  lost  art  in  England 
(mere  meadow  or  prairie  grazing  gradually  superseding  it) 
is  not  named  in  any  part  of  the  discussion  that  I  have 
read. 

I  refer  to  the  cause  which  is  abolishing  the  English  dairy, 
which  drives  us  to  the  commercial  absurdity  of  importing 
fragile  eggs  from  France,  Italy,  Spain,  etc. ,  apples  from 
the  other  side  of  the  Atlantic,  tame  house-fed  rabbits  from 
Belgium,  and  so  on,  with  all  other  ngricultural  products 
Avhich  are  precisely  those  we  are  naturally  best  able  to  pro- 
duce at  home;  I  mean  those  demanding  a  small  area  of 
land  and  a  proportionately  large  amount  of  capital  and  labor. 
A  poultry  or  rabbit  farm,  acre  for  acre,  demands  fully  ten 
times  the  capital,  ten  times  the  labor,  and  yields  ten  times 
the  produce  obtained  by  oflr  big-field  beef  and  mutton 
graziers. 

The  scientific  and  economic  merits  of  ensilage  are  proba- 
bly all  that  is  claimed  for  it,  and  it  is  especially  adapted  for 
our  uncertain  haymaking  climate,  but  what  farmer  who  is 
merely  a  lodger  on  the  land,  holding  it  as  an  annual  tenant- 
at-will  or  under  a  stinted  beggarly  lease  of  21  years,,  would 
expend  his  capital  in  building  a  costly  silo,  which  becomes 
bv  our  feudal  laws  and  usages  the  absolute  propertv  of  the 
landlord  ? 


396  SCIENCE  IN  SHORT  CHAPTERS. 

Our  tenant  farmers  employ  the  latest  and  best  achieve- 
ments of  engineering  science  in  the  form  of  implements, 
but  take  care  that  they  shall  be  upon  wheels,  or  otherwise 
non-fixtures,  and  use  rich  chemically  prepared  manures, 
provided  they  are  not  permanent,  while  they  abstain  from 
improvements  which  involve  any  serious  outlay  in  the  form 
of  fixtures  on  the  land.  Those  who  lecture  them  about  their 
want  of  enterprise  should  always  remember  that  their  con- 
dition is  merely  a  form  of  feudal  serfdom,  tempered  by  the 
possession  of  capital,  and  that  all  their  agricultural  oper- 
ations are  influenced  by  a  continual  struggle  to  prevent 
their  capital  from  falling  into  the  hands  of  the  feudal 
lord.  Anybody  who  has  ever  read  an  ordinary  form  of 
English  farm-lease,  with  its  prohibitions  concerning  the 
sale  of  hay  and  straw,  and  restrictions  to  "four-course," 
or  other  mode  of  cultivation,  must  see  the  hopelessness  of 
any  development  of  British  agriculture  comparable  to  that 
of  British  commerce  and  manufactures. 

Imagine  the  condition  of  a  London  shopkeeper  or  Midland 
manufacturer  holding  his  business  premises  as  a  yearly 
tenant,  liable  at  six  months'  notice  to  quit,  with  confisca- 
tion of  all  his  business  fixtures. 


THE  FKACTURE  OF  COMETS. 

THE  view  of  the  constitution  of  comets  expounded  in  one 
of  my  notes  of  April  last,  viz.,  that  they  are  meteoric  sys- 
tems consisting  of  a  central  mass,  or  masses,  round  which 
a  multitude  of  minor  bodies  are  revolving  like  satellites 
around  their  primary,  is  strongly  confirmed  by  the  curious 
proceedings  of  the  present  comet,  which  proceedings  also 
justify  my  last  note  of  last  month  pointing  out  the  omission 
of  our  astronomers,  who  have  neglected  the  positive  and 
irregular  repulsive  action  of  the  sun  upon  comets,  that, 
like  the  great  comets  of  1843,  1880,  and  1882,  come  within 
a  few  hundred  thousand  miles  of  the  visible  solar  surface. 

The  solar  prominences  are  stupendous  eruptions  from 


77/7?  FRACTURE  OF  COMETS.  397 

the  sun,  consisting,  as  the  spectroscope  demonstrates,  of 
hydrogen  flames  and  incandescent  metallic  vapors  ejected 
with  furious  violence  to  visible  distances  ranging  from  ten. 
or  twenty  to  above  three  hundred  thousand  miles,  but  this 
flame  shown  by  the  spectroscope  is  but  the  flash  of  the  gun, 
the  actual  ejection  proceeding  vastly  farther,  far  beyond 
the  limits  of  the  corona,  as  described  in  last  month's  notes. 
These  eruptions  are  so  abundant  that  Secchi  alone  observed 
and  recorded  2767  in  one  year  (1871).  Speaking  generally, 
the  sun  is  never  free  from  them,  and  they  proceed  from 
all  parts  of  the  sun,  but  most  abundantly  from  the  sun-spot 
/ones. 

A  system  of  meteoric  bodies  such  as  I  suppose  to  form  a 
comet  (I  mean  the  comet  as  it  exists  in  space  before  the 
generation  of  its  tail,  which  is  only  formed  as  it  approaches 
the  .sun)  could  not  approach  so  near  to  the  sun  as  did  the 
present  comet  at  perihelion,  without  encountering  more 
or  less  of  these  furious  blasts  the  flash  of  some  of  which 
have  been  seen  to  move  with  a  measurable  mean  velocity 
of  above  300  miles  per  second,  and  a  probable  maximum 
velocity  sufficient  to  eject  solid  matter  beyond  the  reclaim- 
ing grasp  of  solar  gravitation. 

It  is  evident  that  such  a  meteoric  system  as  I  suppose  to 
constitute  a  comet  would,  iu  the  course  of  a  rapid  perihelion 
flight  crossing  these  outblasts,  be  liable  to  various  degrees 
of  ejection  in  different  parts,  that  would  disturb  its  original 
structure  by  blowing  some  of  its  constituents  out  of  their 
orbits,  or  even  quite  away  from  the  control  of  the  feeble 
gravitation  of  the  general" meteoric  mass,  and  thus  effecting 
a  rupture  of  the  comet. 

Now  such  a  disintegration  or  dispersion  of  the  present 
comet  has  been  actually  observed.  Several  able  observers 
have  described  a  breaking  of  the  head  of  this  comet  shortly 
after  its  perihelion  passage.  Commander  Sampson's  obser- 
vations  with  the  great  26-inch  equatorial  telescope  of  the 
Washington  Naval  Observatory  are  very  explicit.  On  Octo- 
ber 25  he  saw  the  nucleus  as  a  single  well-defined  globular 
body.  On  November  3,  with  the  same  telescope,  he  saw  a 
triple  nucleus,  due  to  the  formation  of  two  additional 
minor  bodies.  These  were  more  distinctly  seen  on  Novem- 


398  SCIENCE  IN  SHORT  CHAPTERS. 

ber  6.  Mr.  W.  E.  Brooks,  of  New  York,  saw  a  detached 
fragment  of  the  comet  which  afterwards  faded  out  of  view. 
Professor  Schmidt  observed  another  and  similar  fragment 
which  has  likewise  disappeared. 

All  these  observations  indicate  disruption  due  to  some 
disturbing  force,  acting  with  different  degrees  of  violence 
upon  different  portions  of  the  comet. 

Minor  disturbances  of  this  kind  will,  I  think,  account 
for  the  trail  of  meteoric  bodies  which  Schiaparelli  has 
shown  to  follow  the  paths  of  other  comets.  A  great  dis- 
turbance might  give  quite  a  new  orbit  to  the  meteoric 
fragments. 

These  considerations  suggest  another  and  a  curious  view 
of  the  question  of  possible  cometary  collision  with  the  sun, 
viz.,  that  a  comet  might  be  traveling  in  such  an  orbit  as  to 
make  it  mathematically  due  to  plunge  obliquely  beneath  the 
solar  surface  at  its  next  perihelion;  but  on  its  approach  to 
the  surface  of  the  sun  it  might  encounter  so  violent  an  out- 
rush  of  solar-prominence  matter  as  to  drive  it  bodily 
out  of  its  course,  and  avert  the  threatened  peril  to  its 
existence. 


THE  ORIGIN  OF  COMETS. 

WE  read  in  story-books  of  uncomfortable  people  who 
have  cherished  a  guilty  secret  in  their  bosoms,  that  it  has 
"gnawed  their  vitals,"  until  at  last  they  have  carried  it 
to  the  grave.  I  have  such  a  secret  that  does  the  gnawing 
business  whenever  I  write  or  speak  of  comets,  concerning 
the  origin  of  which  I  am  guilty  of  an  hypothesis  that  has 
hitherto  been  cherished  as  aforesaid  from  the  very  shame  of 
adding  another  to  an  already  exaggerated  heap  of  specula- 
tions on  celestial  physics. 

It  assumes,  in  the  first  place,  that  all  the  other  suns 
Avhich  we  see  as  stars  are  constituted  like  our  own  sun; 
that  they  eject  great  eruptions  similar  to  the  prominences 
above  described,  and  even  of  vastly  greater  magnitude,  as  in 
the  case  of  the  flashing  stars  that  have  excited  so  much 


THE  ORIGIN  OF  COMETS.  399 

wonderment  among  astronomers,  but  which  I  regard  simply 
as  suns  like  ours,  subject,  like  ours,  to  periodic  maximum 
and  minimum  activities,  but  of  greater  magnitude. 

If  such  is  the  case,  some  of  the  prominence  matter  or 
vaporous  constituents  of  these  suns  must  be  ejected  with 
much  greater  proportional  violence  than  are  those  from  our 
sun.  But  those  from  our  sun  have  been  proved  to  rush  out 
on  some  occasions  with  a  velocity  so  great  that  the  solar 
gravitation  cannot  bring  them  back.  If  such  is  ever  the 
case  with  the  explosions  of  our  sun,  it  must  be  of  frequent 
occurrence  with  the  greater  explosions  of  certain  stars,  and 
therefore  vast  quantities  of  meteoric  matter  are  continually 
ejected  into  space,  and  traveling  there  until  they  come 
within  the  gravitation  domain  of  some  other  sun  like  ours, 
when  they  will  necessarily  be  bent  into  such  orbits  as  those 
of  comets. 

But  what  will  be  the  nature  of  this  meteoric  matter  ? 

If  from  our  sun,  it  would  be  a  multitude  of  metallic 
hailstones,  due  to  the  condensation  of  the  metallic  vapor 
by  cooling  as  it  leaves  the  sun,  and  such  meteoric  hail 
would  correspond  to  the  meteoric  stones  that  fall  upon  our 
earth,  and  which,  for  reasons  stated  in  "  The  Fuel  of  the 
Sun,"  I  believe  to  be  of  solar  origin.  Besides  these,  there 
would  be  ice-hail,  such  as  Schevedorf  claims  to  be  meteoric. 

A  star  mainly  composed  of  hydrogen  and  carbon,  or 
densely  enveloped  in  these  gases  (as  the  spectroscope  indi- 
cates to  be  the  case  in  some  of  these  flashing  stars),  would 
eject  hydrocarbon  vapors,  condensible  by  cooling  into 
solids  similar  to  those  we  obtain  by  the  condensation  of 
terrestrial  hydrocarbon  vapors  (paraffin,  camphor,  turpen- 
tine, and  all  the  essential  oils,  for  example),  and  thus  we 
should  have  the  meteoric  systems  composed  of  these  parti- 
cles circulating  about  their  own  common  centr&of  mass  as 
above  stated,  and  displaying  the  spectrum,  jfrhich  Dr. 
Huggins  has  found  common  to  comets.  \ 

If  this  is  correct,  the  present  comet  comes  from  a  sun 
that  contains  metallic  sodium  in  addition  to  tu,e  hydro- 
carbons, as  the  spectrum  of  this  metal  was  seen  when  this 
comet  was  near  enough  to  the  sun  to  render  its  vapor 
incandescent. 


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